33 Commits

Author SHA1 Message Date
Michael Roitzsch
c9193777b2 internals: update for macOS 15.2 Sequoia 2024-12-13 10:11:36 +01:00
Michael Roitzsch
58817482b7 Makefile: select last of multiple simulators
support multiple installed simulators for iOS, tvOS, watchOS
2024-12-12 12:53:54 +01:00
Michael Roitzsch
039fa246de internals: update for macOS 15.0 Sequoia 2024-09-10 13:42:16 +02:00
Michael Roitzsch
2c989cabcf Makefile: extend plist extraction
add LaunchAngels and NanoLaunchDaemons to plist extraction
2024-07-15 11:54:47 +02:00
Michael Roitzsch
d74406462a Makefile: root-only folders in simulators
/private/var/db/modelmanagerd is a new root-only folder in the simulators
2024-06-28 14:49:19 +02:00
Michael Roitzsch
bfc608e30e flake: update for Xcode 16.0 2024-06-28 14:48:17 +02:00
Michael Roitzsch
305fe81fa6 internals: add watchdog 2024-04-24 13:02:23 +02:00
Chas. J. Owens IV
9a3d767be2 Added Watchdog 2024-04-22 15:45:27 -04:00
Michael Roitzsch
ef3cb1d7aa internals: update for macOS 14.4 Sonoma 2024-03-17 11:33:06 +01:00
Michael Roitzsch
e2ae918b3f flake: update for Xcode 15.2 2024-03-17 11:32:04 +01:00
Michael Roitzsch
093a04de7f flake: cleanup 2024-01-17 19:40:03 +01:00
Michael Roitzsch
61ff7f899f flake: load snapshot-header the non-flake way
it’s a fixed version that does not participate in 'nix flake update'
2024-01-17 19:39:49 +01:00
Michael Roitzsch
b5166d34f4 internals: update for macOS 14.2 Sonoma 2023-12-13 16:12:03 +01:00
Michael Roitzsch
1c959c27bb Makefile: iOS simulator now also in mounted image 2023-10-29 18:55:40 +01:00
Michael Roitzsch
4e5147d0c8 flake: update for Xcode 15.0.1 2023-10-29 18:54:21 +01:00
Michael Roitzsch
add57def1e internals: update for macOS 13.5 Ventura 2023-08-20 20:55:46 +02:00
Michael Roitzsch
4ed7ef68db flake: update for Xcode 14.3.1
makeSetupHook parameters changed
2023-08-20 20:55:46 +02:00
Michael Roitzsch
9d57a5527f Makefile: catch Nix build errors early 2023-08-20 20:55:46 +02:00
Michael Roitzsch
afaa4c55e5 Makefile: fix wildcard resolution 2023-08-20 20:55:38 +02:00
Michael Roitzsch
9db223a1dc flake: fix sandboxed builds
disable sandboxing when we symlink the platform Xcode
2023-04-29 16:02:22 +02:00
Michael Roitzsch
af5c420f43 internals: update for macOS 13.4 Ventura 2023-04-02 15:25:56 +02:00
Michael Roitzsch
eeab6a8bfa Makefile: scan Xcode templates for extensions
extension definitions and their extension point names appear in Xcode
project templates
• scan all of Xcode’s Developer directory, not just selected subdirs
• extract plist part regarding extensions from TemplateInfo.plist files
• check for macOS and iOS extension keys
2023-04-02 12:04:55 +02:00
Michael Roitzsch
4d8f14e4a6 Makefile: silence Nix git dirty warning 2023-04-02 09:06:16 +02:00
Michael Roitzsch
04d82534d8 flake: update for Xcode 14.3 2023-04-02 09:05:36 +02:00
Michael Roitzsch
9542568442 internals: update for macOS 13.2 Ventura 2022-12-26 18:33:03 +01:00
Michael Roitzsch
05eed46555 flake: update for Xcode 14.2 2022-12-26 10:02:28 +01:00
Michael Roitzsch
72af1896ec flake: update for Xcode 14.1 2022-11-06 20:37:58 +01:00
Michael Roitzsch
40b2576d55 internals: update for macOS 12.4 Monterey 2022-06-06 21:45:17 +02:00
Michael Roitzsch
909ec8a160 flake: update for Xcode 13.4 2022-05-25 18:45:24 +02:00
Michael Roitzsch
b92ed8e175 internals: update for macOS 12.3 Monterey 2022-03-25 08:20:11 +01:00
Michael Roitzsch
e33fabd772 flake: update for Xcode 13.3 2022-03-25 08:19:46 +01:00
Michael Roitzsch
b494b38956 flake: update for Xcode 13.2 2022-01-02 15:02:24 +01:00
Michael Roitzsch
8d62d3e215 formally conform to the TSV file format
• move internals.txt to internals.tsv (bonus: GitHub built-in rendering)
• add a header in the first line
• ignore first line for sort checking
• ignore first line for HTML rendering
2022-01-02 15:02:24 +01:00
5 changed files with 234 additions and 139 deletions

View File

@@ -9,8 +9,9 @@ CHECK_TARGETS = check_files check_binaries check_manifests check_services
all: $(DB).lz check
ifneq ($(wildcard $(MY_INTERNALS)),)
internals.txt: $(MY_INTERNALS)
textutil -cat txt "$<" -output $@
internals.tsv: $(MY_INTERNALS)
printf 'Term\tDescription\n' > $@
textutil -cat txt $@ "$<" -output $@
xattr -c $@
endif
@@ -27,8 +28,8 @@ $(DB).lz: $(DB)
rm -rf dyld
endif
check: internals.txt
@LANG=en sort --ignore-case $< | diff -uw $< -
check: internals.tsv
@(head --lines=1 ; LANG=en sort --ignore-case) < $< | diff -uw $< -
@$(MAKE) --silent --jobs=1 $(CHECK_TARGETS)
define VIEW
@@ -49,12 +50,17 @@ sqlite: $(DB)
# MARK: - data extraction helpers
ACEXTRACT = $(shell nix build --no-write-lock-file .\#acextract && \
ACEXTRACT = $(shell nix build --no-write-lock-file --no-warn-dirty .\#acextract && \
readlink result && rm result)/bin/acextract
DSCEXTRACTOR = $(shell nix build --no-write-lock-file .\#dsc-extractor && \
DSCEXTRACTOR = $(shell nix build --no-write-lock-file --no-warn-dirty .\#dsc-extractor && \
readlink result && rm result)/bin/dyld-shared-cache-extractor
dyld: /System/Library/dyld/dyld_shared_cache_$(shell uname -m) /System/DriverKit/System/Library/dyld/dyld_shared_cache_$(shell uname -m)
$(DB_TARGETS)::
# evaluate helper tools to catch Nix build errors early
: $(ACEXTRACT)
: $(DSCEXTRACTOR)
dyld: /System/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_x86_64h /System/Cryptexes/OS/System/DriverKit/System/Library/dyld/dyld_shared_cache_x86_64h
if ! test -x $(DSCEXTRACTOR) ; then \
printf '\033[1mdscextractor tool unavailable\033[m\n' >&2 ; \
echo 'FAIL;' ; \
@@ -68,19 +74,19 @@ XCODE = $(lastword $(wildcard /Applications/Xcode.app /Applications/Xcode-beta.a
prefix = $$(case $(1) in \
(macOS) ;; \
(macOS-dyld) echo $(dir $(realpath $(firstword $(MAKEFILE_LIST))))/dyld ;; \
(iOS) echo $(XCODE)/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot ;; \
(tvOS) echo $(XCODE)/Contents/Developer/Platforms/AppleTVOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/tvOS.simruntime/Contents/Resources/RuntimeRoot ;; \
(watchOS) echo $(XCODE)/Contents/Developer/Platforms/WatchOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/watchOS.simruntime/Contents/Resources/RuntimeRoot ;; \
(iOS) echo $(lastword $(wildcard /Library/Developer/CoreSimulator/Volumes/iOS_*/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS*.simruntime/Contents/Resources/RuntimeRoot)) ;; \
(tvOS) echo $(lastword $(wildcard /Library/Developer/CoreSimulator/Volumes/tvOS_*/Library/Developer/CoreSimulator/Profiles/Runtimes/tvOS*.simruntime/Contents/Resources/RuntimeRoot)) ;; \
(watchOS) echo $(lastword $(wildcard /Library/Developer/CoreSimulator/Volumes/watchOS_*/Library/Developer/CoreSimulator/Profiles/Runtimes/watchOS*.simruntime/Contents/Resources/RuntimeRoot)) ;; \
esac)
find = \
{ \
$(2) find /Library /System /bin /dev /private /sbin /usr ! \( -path /System/Volumes/Data -prune \) $(1) 2> /dev/null | sed 's/^/macOS /' ; \
cd $(XCODE)/Contents/Developer ; find Library Toolchains Tools usr $(1) | sed 's|^|macOS /Applications/Xcode.app/Contents/Developer/|' ; \
$(2) find /Library /System /bin /dev /private /sbin /usr ! \( -path /Library/Developer/CoreSimulator/Volumes -prune \) ! \( -path /System/Volumes/Data -prune \) $(1) 2> /dev/null | sed 's/^/macOS /' ; \
find $(XCODE)/Contents/Developer $(1) | sed 's|^$(XCODE)|macOS /Applications/Xcode.app|' ; \
test -d "$(call prefix,macOS-dyld)" && cd "$(call prefix,macOS-dyld)" && find . $(1) | sed '1d;s/^\./macOS-dyld /' ; \
cd $(call prefix,iOS) ; find . $(1) | sed '1d;s/^\./iOS /' ; \
cd $(call prefix,tvOS) ; find . $(1) | sed '1d;s/^\./tvOS /' ; \
cd $(call prefix,watchOS) ; find . $(1) | sed '1d;s/^\./watchOS /' ; \
cd "$(call prefix,iOS)" ; $(2) find . $(1) 2> /dev/null | sed '1d;s/^\./iOS /' ; \
cd "$(call prefix,tvOS)" ; $(2) find . $(1) 2> /dev/null | sed '1d;s/^\./tvOS /' ; \
cd "$(call prefix,watchOS)" ; $(2) find . $(1) 2> /dev/null | sed '1d;s/^\./watchOS /' ; \
}
file = SELECT id, $(1) FROM files WHERE os = '$$os' AND path = '$$(echo "$$path" | sed "s/'/''/g")'
@@ -134,6 +140,17 @@ db_manifests::
test -r "$(call prefix,$$os)$$path" && plutil -convert json "$(call prefix,$$os)$$path" -o - | \
sed "/: invalid object/d;s/'/''/g;s|.*|INSERT INTO info $(call file,json('&'));\n|" ; \
done
$(call find,-type f -name 'TemplateInfo.plist') | while read -r os path ; do \
test -r "$(call prefix,$$os)$$path" && { \
echo '<dict>' ; \
PlistBuddy -c 'Print Definitions:Info.plist\:NSExtension' "$(call prefix,$$os)$$path" ; \
PlistBuddy -c 'Print Definitions:Info.plist\:EXAppExtensionAttributes' "$(call prefix,$$os)$$path" ; \
PlistBuddy -c 'Print Options:0:Units:Swift:Definitions:Info.plist\:NSExtension' "$(call prefix,$$os)$$path" ; \
PlistBuddy -c 'Print Options:0:Units:Swift:Definitions:Info.plist\:EXAppExtensionAttributes' "$(call prefix,$$os)$$path" ; \
echo '</dict>' ; \
} 2> /dev/null | plutil -convert json - -o - | \
sed "/Property List error:/d;s/'/''/g;s|.*|INSERT INTO info $(call file,json('&'));\n|" ; \
done
db_assets::
if ! test -x $(ACEXTRACT) ; then \
@@ -153,8 +170,8 @@ db_services::
printf '\033[1mcollecting launchd service information...\033[m\n' >&2
echo 'DROP TABLE IF EXISTS services;'
echo 'CREATE TABLE services (id INTEGER REFERENCES files, kind TEXT, plist JSON);'
$(call find,-type f -name '*.plist' -path '*/LaunchAgents/*' -o -path '*/LaunchDaemons/*') | while read -r os path ; do \
case "$$path" in (*/LaunchAgents/*) kind=agent ;; (*/LaunchDaemons/*) kind=daemon ;; esac ; \
$(call find,-type f -name '*.plist' -path '*/LaunchAgents/*' -o -path '*/LaunchAngels/*' -o -path '*/LaunchDaemons/*' -o -path '*/NanoLaunchDaemons/*') | while read -r os path ; do \
case "$$path" in (*/LaunchAgents/*) kind=agent ;; (*/LaunchAngels/*) kind=angel ;; (*/LaunchDaemons/*) kind=daemon ;; (*/NanoLaunchDaemons/*) kind=daemon-nano ;; esac ; \
test -r "$(call prefix,$$os)$$path" && plutil -convert json "$(call prefix,$$os)$$path" -o - | \
sed "s/'/''/g;s|.*|INSERT INTO services $(call file,'$$kind'$(,)json('&'));\n|" ; \
done
@@ -163,15 +180,15 @@ $(DB_TARGETS)::
echo 'COMMIT TRANSACTION;'
# MARK: - check targets for internals.txt
# MARK: - check targets for internals.tsv
check_files: internals.txt $(DB)
check_files: internals.tsv $(DB)
printf '\033[1mchecking files...\033[m\n' >&2
grep -ow '~\?/[^,;]*' $< | sed -E 's/ \(.*\)$$//;s/^\/(etc|var)\//\/private&/' | \
sed "s/'/''/g;s|.*|SELECT count(*), '&' FROM files WHERE path GLOB '&';|" | \
sqlite3 $(DB) | sed -n "/^0|/{s/^0|//;p;}"
check_binaries: internals.txt $(DB)
check_binaries: internals.tsv $(DB)
printf '\033[1mchecking command line tools...\033[m\n' >&2
grep -o 'command line tools\?: [^;]*' $< | sed 's/^[^:]*: //;s/ //g;s/([^)]*)//g' | tr , '\n' | \
sed "s/'/''/g;s|.*|SELECT count(*), '&' FROM files WHERE executable = true AND path GLOB '*/&';|" | \
@@ -185,13 +202,13 @@ check_binaries: internals.txt $(DB)
sed "s/'/''/g;s/.*/SELECT count(*), '&' FROM strings WHERE string GLOB '*&*';/" | \
sqlite3 $(DB) | sed -n "/^0|/{s/^0|//;p;}"
check_manifests: internals.txt $(DB)
check_manifests: internals.tsv $(DB)
printf '\033[1mchecking extension points...\033[m\n' >&2
grep -o 'extension points\?: [^;]*' $< | sed 's/^[^:]*: //;s/ //g;s/([^)]*)//g' | tr , '\n' | \
sed "s/'/''/g;s|.*|SELECT count(*), '&' FROM info, json_each(plist, '$$.NSExtension') WHERE key = 'NSExtensionPointIdentifier' AND value = '&';|" | \
sed "s/'/''/g;s|.*|SELECT count(*), '&' FROM (SELECT value FROM info, json_each(plist, '$$.NSExtension') WHERE key = 'NSExtensionPointIdentifier' UNION SELECT value FROM info, json_each(plist, '$$.EXAppExtensionAttributes') WHERE key = 'EXExtensionPointIdentifier') WHERE value = '&';|" | \
sqlite3 $(DB) | sed -n "/^0|/{s/^0|//;p;}"
check_services: internals.txt $(DB)
check_services: internals.tsv $(DB)
printf '\033[1mchecking launchd services...\033[m\n' >&2
grep -o 'launchd services\?: [^;]*' $< | sed 's/^[^:]*: //;s/ //g;s/([^)]*)//g' | tr , '\n' | \
sed "s/'/''/g;s|.*|SELECT count(*), '&' FROM services, json_each(plist) WHERE key = 'Label' AND value = '&';|" | \

34
flake.lock generated
View File

@@ -35,11 +35,11 @@
"dsc-extractor": {
"flake": false,
"locked": {
"lastModified": 1628793863,
"narHash": "sha256-AOwiwoEE8xYzxhkX7RCkLaiArNZAV2GJWbpqLbKOaXY=",
"lastModified": 1702321461,
"narHash": "sha256-bV0MesIw0lVrhNuEkfexTFhQ73EynryQskvk8egecEs=",
"owner": "keith",
"repo": "dyld-shared-cache-extractor",
"rev": "9ef13238a8f5717165c91291212d6f32617ab67e",
"rev": "c28b25abf09d9affa96fc1bdcaa6d7aef1f64032",
"type": "github"
},
"original": {
@@ -50,16 +50,15 @@
},
"nixpkgs": {
"locked": {
"lastModified": 1633422745,
"narHash": "sha256-gA6Ok64nPbkjHk3Oanq4641EeYkjcKhisDF9wBjLxEk=",
"lastModified": 1719468428,
"narHash": "sha256-vN5xJAZ4UGREEglh3lfbbkIj+MPEYMuqewMn4atZFaQ=",
"owner": "NixOS",
"repo": "nixpkgs",
"rev": "8e1eab9eae4278c9bb1dcae426848a581943db5a",
"rev": "1e3deb3d8a86a870d925760db1a5adecc64d329d",
"type": "github"
},
"original": {
"id": "nixpkgs",
"ref": "nixpkgs-unstable",
"type": "indirect"
}
},
@@ -69,18 +68,17 @@
"command-line": "command-line",
"dsc-extractor": "dsc-extractor",
"nixpkgs": "nixpkgs",
"snap-util": "snap-util",
"snapshot-header": "snapshot-header"
"snap-util": "snap-util"
}
},
"snap-util": {
"flake": false,
"locked": {
"lastModified": 1630855703,
"narHash": "sha256-r89y29BL/U6LEWhdLPn1TUvFz4IyEg0FexkD3UNdAUU=",
"lastModified": 1647211082,
"narHash": "sha256-zQ/0Cpo6CCeKXafeERjBCQ2gv9396c7UZU+VmViQVIc=",
"owner": "ahl",
"repo": "apfs",
"rev": "1cb945d598534bd3a0e26cae04a626993b5e6941",
"rev": "2bcf604966949f618e6a6ce33ca8ae1721494e6d",
"type": "github"
},
"original": {
@@ -88,18 +86,6 @@
"repo": "apfs",
"type": "github"
}
},
"snapshot-header": {
"flake": false,
"locked": {
"narHash": "sha256-Y/DTtpnT8JQZO5Ijr+tW0IrIOuECcJ+ZvFLCgwrFt2M=",
"type": "tarball",
"url": "https://opensource.apple.com/tarballs/xnu/xnu-6153.141.1.tar.gz"
},
"original": {
"type": "tarball",
"url": "https://opensource.apple.com/tarballs/xnu/xnu-6153.141.1.tar.gz"
}
}
},
"root": "root",

View File

@@ -13,27 +13,33 @@
url = "github:keith/dyld-shared-cache-extractor";
flake = false;
};
snapshot-header = {
url = "https://opensource.apple.com/tarballs/xnu/xnu-6153.141.1.tar.gz";
flake = false;
};
snap-util = {
url = "github:ahl/apfs";
flake = false;
};
nixpkgs.url = "flake:nixpkgs/nixpkgs-unstable";
};
outputs = { self, nixpkgs, acextract, command-line, dsc-extractor, snapshot-header, snap-util }: {
packages.x86_64-darwin = {
outputs = { self, nixpkgs, acextract, command-line, dsc-extractor, snap-util }: {
packages.x86_64-darwin = let
xcode = (nixpkgs.legacyPackages.x86_64-darwin.xcodeenv.composeXcodeWrapper {
version = "16.0";
}).overrideAttrs (attrs: { buildCommand = ''
# see https://github.com/NixOS/nixpkgs/pull/322641
set +o pipefail
'' + attrs.buildCommand; });
in {
acextract =
with import nixpkgs { system = "x86_64-darwin"; };
let xcode = makeSetupHook {
deps = [ (xcodeenv.composeXcodeWrapper { version = "13.1"; }) ];
with nixpkgs.legacyPackages.x86_64-darwin;
let xcodeHook = makeSetupHook {
name = "xcode-hook";
propagatedBuildInputs = [ xcode ];
} "${xcbuildHook}/nix-support/setup-hook";
in stdenv.mkDerivation {
name = "acextract-${lib.substring 0 8 self.inputs.acextract.lastModifiedDate}";
src = acextract;
nativeBuildInputs = [ xcode ];
nativeBuildInputs = [ xcodeHook ];
__noChroot = true;
preBuild = "LD=$CC";
# FIXME: want to have submodule support for Nix flakes, workaround by explicit instantiation
postUnpack = "rmdir source/CommandLine ; ln -s ${command-line} source/CommandLine";
@@ -77,19 +83,27 @@
'';
dontStrip = true;
};
dsc-extractor =
with import nixpkgs { system = "x86_64-darwin"; };
rustPlatform.buildRustPackage {
with nixpkgs.legacyPackages.x86_64-darwin;
stdenv.mkDerivation {
name = "dsc-extractor-${lib.substring 0 8 self.inputs.dsc-extractor.lastModifiedDate}";
src = dsc-extractor;
cargoHash = "sha256-Z405Q9gV/mJL2WtCstZ+Y9rEw32zgwU1RiYaAjkIcfw=";
nativeBuildInputs = [ cmake ];
};
snap-util =
with import nixpkgs { system = "x86_64-darwin"; };
stdenv.mkDerivation {
with nixpkgs.legacyPackages.x86_64-darwin;
let snapshot-header = fetchFromGitHub {
owner = "apple";
repo = "darwin-xnu";
rev = "xnu-6153.141.1";
hash = "sha256-/2aR6n5CbUobwbxkrGqBOAhCZLwDdIsoIOcpALhAUF8=";
};
in stdenv.mkDerivation {
name = "snap-util-${lib.substring 0 8 self.inputs.snap-util.lastModifiedDate}";
src = snap-util;
nativeBuildInputs = [ (xcodeenv.composeXcodeWrapper { version = "13.1"; }) ];
nativeBuildInputs = [ xcode ];
preBuild = "NIX_CFLAGS_COMPILE='-idirafter ${snapshot-header}/bsd'";
installPhase = ''
mkdir -p $out/bin
@@ -108,6 +122,7 @@
EOF
chmod a+x $out/bin/snapUtil
'';
__noChroot = true;
postFixup = ''
cat > snapUtil.entitlements <<- EOF
<?xml version="1.0" encoding="UTF-8"?>

View File

@@ -12,7 +12,7 @@ class Converter {
generate() {
const dl = document.createElement("dl");
dl.setAttribute("class", "row");
for (const rowText of this.text.split("\n"))
for (const rowText of this.text.split("\n").slice(1))
if (rowText.length && rowText.toLowerCase().includes(this.filter.toLowerCase()))
dl.append.apply(dl, this.generateRow(rowText));
return dl;
@@ -54,7 +54,7 @@ class Converter {
document.addEventListener("DOMContentLoaded", event => {
// load main content
fetch("internals.txt").then(function(response) {
fetch("internals.tsv").then(function(response) {
if (!response.ok) return "";
return response.text();
}).then(function(text) {

View File

@@ -1,54 +1,63 @@
Term Description
1TR One True Recovery; booting into macOS recovery on Apple Silicon by holding the power button to verify physical presence; enables interaction with SEP to change Boot Policy
AA Apple account
AA Apple Account
AA Apple Archive, see also Apple Encrypted Archive; command line tools: aa, aea, compression_tool
AAC Automatic Assessment Configuration; AutomaticAssessmentConfiguration.framework; puts device in a locked mode for exam-style test applications
AAT Apple Advanced Typography; font format and rendering engine
Accounts launchd service: com.apple.accountsd; /System/Library/Accounts
ACDE Apple Connect Device External? ACDEClient.framework, old two-step verification, derived from a company-internal AppleConnect system? server: appleconnect.apple.com
ACDC Apple Chips in Data Centers; see PCC
ACDE Apple Connect Device External? ACDEClient.framework, old two-step verification, derived from a company-internal AppleConnect system?
ACFS Apple Clustered File System; deprecated file system for Xsan; acfs.framework
Acoustic ID Siri feature to recognize songs
Acoustic ID song recognition and matching with Apple catalog, playback on HomePod; /System/Library/Components/AudioDSP.component
Activation cryptographic check-in with iCloud to lock devices reported by the user as lost; verified by iBoot; MobileActivationMacOS.framework; launchd service: com.apple.mobileactivationd; servers: humb.apple.com, albert.apple.com
Activity jobs, coarse-grained work units of applications; tracked by the system across XPC, bears a QoS class for scheduling; low-level mechanism not to be confused with User Activity
AE Apple Events; messaging system to invoke application functionality; CoreServices.framework/AE.framework; launchd services: com.apple.coreservices.appleevents, com.apple.AEServer (AE over network)
AEA Apple Encrypted Archive; command line tool: aea
Aegir astronomy watch face and lock screen; /System/Library/CoreServices/AegirProxyApp.app
AFM Apple Foundation Model; pre-trained transformer and diffusion models for Greymatter, optimized for on-device use by quantization (with accuracy-recovery adapters) and palletization; command line tool: modelcatalogdump
AGC Apple Graphics Control, management of multiple displays and display port connections; launchd service: com.apple.displaypolicyd
AHAP Apple Haptic Audio Pattern; file format for simultaneous audio and haptic data; CoreHaptics.framework
AIR Apple Intermediate Representation; synthetic bytecode architecture target for GPU binary toolchain
ALF Application-Level Firewall, launchd service: com.apple.alf (socketfilterfw)
ALF Application-Layer Firewall; implemented as a Network Extension (see System Extension); launchd service: com.apple.alf (socketfilterfw); command line tool: socketfilterfw
Alloy substrate for communication between user devices over Bluetooth and devices to iCloud, implemented over IDS; /System/Library/IdentityServices/ServiceDefinitions; launchd service: com.apple.identityservicesd
ALS Ambient Light Sensor, AmbientDisplay.framework
Amber Swift UI; SwiftUI.framework
AMFI Apple Mobile File Integrity, checks code integrity based on code signature, stronger enforcement with hardened runtime, validates entitlement restrictions; launchd service: com.apple.MobileFileIntegrity (amfid, invoked by kernel through host special port 18); disabled by setting amfi_get_out_of_my_way=0x1 in boot-args
AMFI Apple Mobile File Integrity, checks code integrity based on code signature, stronger enforcement with hardened runtime, validates entitlement restrictions and environment constraints (launch constraints, library constraints); launchd service: com.apple.MobileFileIntegrity (amfid, invoked by kernel through host special port 18); disabled by setting amfi_get_out_of_my_way=0x1 in boot-args
AMP Apple Media Protocol? former parts of iTunes for iPod and iOS device access in Finder, Home Sharing; AMPDevices.framework, AMPSharing.framework; launchd services: com.apple.AMPDeviceDiscoveryAgent, com.apple.AMPDevicesAgent, com.apple.amp.mediasharingd
AMP Asynchronous Multiprocessing; performance and power-efficiency cores on Apple Silicon
AMS Apple Media Services; formerly the iTunes stores and media services: App Stores, Apple Music, Apple TV, iCloud media library, Apple Podcasts, Podcast sync, Books Store, Books sync; AppleMediaServices.framework; server: phobos.apple.com
AMX Apple Matrix Extension; ARM instruction set extension for matrix operations
ANE Apple Neural Engine, hardware accelerator for neural network operations; ANECompiler.framework, ANEServices.framework; launchd service: com.apple.aned
Anisette two-factor authentication creates security codes on trusted devices using TOTP, probably using Circle keys, checked by HSA; AuthKit.framework; launchd service: com.apple.akd
AOP Always On Processor, part of Apple SoCs, runs RTKit as operating system
AOS Apple Online Services? historical name for iCloud
Apache built-in web server; command line tool: apachectl
APFS Apple File System; copy-on-write file system with support for volume space-sharing, per-file encryption, and snapshots
APNS Apple Push Notification service, server infrastructure for remote push notifications over a single connection, clients subscribe to push topics, can be authenticated by app (remote notifications), device (Find My …), or Apple ID login (DSID); credentials in apsd keychain; launchd service: com.apple.apsd; server: push.apple.com
APNS Apple Push Notification service, server infrastructure for remote push notifications over a single connection, clients subscribe to push topics, can be authenticated by app (remote notifications), device (Find My …), or Apple Account login (DSID); credentials in apsd keychain; launchd service: com.apple.apsd; server: push.apple.com
App Nap quiescence detection for applications and corresponding self-demotion in scheduler parameters, implemented within application frameworks and RunningBoard, listens for occlusion notifications from WindowServer
App Sandbox Seatbelt-based sandbox for apps; /System/Library/Sandbox/Profiles/application.sb; enabled with com.apple.security.app-sandbox entitlement; launchd service: com.apple.secinitd
AppleCare extended warranty; NewDeviceOutreach.framework; launchd service: com.apple.ndoagent
APT Adaptive Picture Timing? ProMotion; dynamic screen updates with 120Hz base frequency; AppleDisplayTCONControl.framework
Ask To parental-controlled user can ask parent for exceptions; launchd service: com.apple.asktod; AskToCore.framework
ASL Apple System Logger, superseded by Unified Logging; /etc/asl; stored in /var/log/asl; launchd service: com.apple.syslogd; command line tool: syslog
ASR Apple Software Restore; restore entire volumes from sources like disk images (HDI, SIU), also restores based on APFS snapshots and snapshot deltas; command line tool: asr
Assertions power state management allowing applications to prevent sleeping; launchd service: com.apple.powerd; command line tools: caffeinate, pmset
Assessment checking of System Policy; term also used for AAC
Asset Cache discretionary caching server for Mobile Assets, Packages, iOS updates, App Store content, ODR, MMCS data; launchd services: com.apple.AssetCache.builtin, com.apple.AssetCacheLocatorService, com.apple.AssetCacheManagerService, com.apple.AssetCacheTetheratorService; command line tools: AssetCacheLocatorUtil, AssetCacheManagerUtil, AssetCacheTetheratorUtil
Assistant Siri; dictation and semantic understanding, Intent is communicated to and enacted on the client, uses TTS; /System/Library/Assistant, AssistantServices.framework; server: *.siri.apple.com
Assistant Siri; speech recognition and semantic understanding, dialog management by CDM, Intent is communicated to and enacted on the client, uses TTS for speech output, Snippets to embed mini UIs into responses; /System/Library/Assistant, /System/Library/Snippets, AssistantServices.framework; server: *.siri.apple.com
ATS App Transport Security, sandbox mechanism only allowing TLS-secured connections
ATSUI Apple Type Services for Unicode Imaging; rendering engine superseded by CoreText.framework, font management; ApplicationServices.framework/ATS.framework; launchd service: com.apple.xtyped (fontd); command line tools: atsutil
ATT App Tracking Transparency; apps declare user tracking on app store
Attestation cryptographic proof of a genuine SEP; used for web authentication and app attestation; DeviceCheck.framework; online service signs a GID-based challenge response? used to pair RemoteXPC channel? stripped down variant used to securely identify Touch ID keyboards
Attestation cryptographic proof of a genuine SEP; used for web authentication and app attestation; DeviceCheck.framework; SEP responds to challenge using hardware-key (GID, PKA), online service verifies; used to pair Touch ID keyboards, used to pair RemoteXPC channel?
Authorization discretionary access control policies for high-level services; similar to PAM; policy stored in /var/db/auth.db
Avatar Memoji and Animoji (face tracking); AvatarKit.framework
AVB Audio Video Bridging, low-latency audio over Ethernet; launchd service: com.apple.avbdeviced; command line tool: avbdiagnose, avbutil
Avatar Memoji and Animoji, including pre-rendered iMessage stickers; AvatarKit.framework
AVB Audio Video Bridging, low-latency audio over Ethernet; launchd service: com.apple.avbdeviced; command line tools: avbanalyse, avbdiagnose, avbutil
AWD Apple Wireless Diagnostics, sends system telemetry to Apple; CoreAnalytics.framework, WirelessDiagnostics.framework; launchd services: com.apple.awdd, com.apple.analyticsd
AWDL Apple Wireless Direct Link; secondary WiFi interface that runs in parallel to an active WiFi access point connection, similar to WiFi Direct (p2p interface), uses a randomized MAC, used for peer-to-peer networking: AirDrop, AirPlay; DeviceToDeviceManager.framework
Background Assets assets that an app extension loads without the app being launched; BackgroundAssets.framework; extension point: com.apple.background-asset-downloader-extension; launchd service: com.apple.backgroundassets.user
Bezel on-screen overlays for hardware volume buttons, screen brightness, Bluetooth HID, and others; /Library/Application Support/Apple/BezelServices, launchd services: com.apple.loginwindow, com.apple.OSDUIHelper
Biome CloudKit-based datastream and sync engine; BiomeStreams.framework, BiomeSync.framework; launchd services: com.apple.BiomeAgent, com.apple.biomesyncd
Blast Door sandboxed sanitization process for untrusted iMessage input; BlastDoor.framework
Bifrost emergency satellite connectivity; /System/Library/LocationBundles/Bifrost.bundle
Biome CloudKit-synced streaming and storage of events like donated and invoked Intents; semantic index to ground AI with personal context; BiomeStreams.framework, BiomeSync.framework; launchd services: com.apple.BiomeAgent, com.apple.biomesyncd; embedding vector extraction and storage: ZeoliteFramework.framework
Blast Door sandboxed sanitization process for untrusted input, used for iMessage, IDS, Telephony, media analysis; BlastDoor.framework, CTBlastDoorSupport.framework, IDSBlastDoorSupport.framework, MediaAnalysisBlastDoorSupport.framework, MessagesBlastDoorSupport.framework, TelephonyBlastDoorSupport.framework
BOM Bill of Materials; format to store contents of installer Packages; command line tool: lsbom
Bonjour mDNS; launchd service: com.apple.mDNSResponder.reloaded; command line tool: dns-sd
Boot Cache disk cache pre-heating at boot time with typically loaded applications; /var/db/BootCaches; launchd service: com.apple.warmd
@@ -60,174 +69,224 @@ Bulletin Board application push notification management, aggregates local and re
Cache Delete cleanup for various caches; /System/Library/CacheDelete; launchd service: com.apple.cache_delete (deleted)
CAML Core Animation Markup Language; XML file format for layers, shapes and animations
Carousel derivative of SpringBoard for Watch home screen, watch face, and notification center
Celestial media streaming used by ReplayKit for game broadcasts; Celestial.framework
CBOR Concise Binary Object Representation; JSON-inspired compact binary data serialization; CBORLibrary.framework
CDHash Code Directory Hash; a hash of hashes over the parts of a code bundle; command line tool: codesign
CDM Continuous Dialog Manager; natural dialog with Siri, MARRS for multi-modality; ContinuousDialogManagerService.framework
CEC Consumer Electronics Control; remote control for HDMI-connected devices; CoreRC.framework, IOCEC.framework
Celestial media streaming used by ReplayKit for in-app screen broadcasts; Celestial.framework; launchd service: com.apple.replayd
Certificates validity checked using CRLs, OCSP stapling, and transparency logs; /System/Library/Security/Certificates.bundle; launchd services: com.apple.trustd, com.apple.trustd.agent, com.apple.ocspd; command line tool: crlrefresh
Circle cryptographic primitive to exchange public keys of all trusted devices of one user, signed by all Circle peers; iCloud identity keypair as an additional Circle peer, triggers countersigning from all trusted devices, private key synced across all trusted devices, new devices can pull this key from Secure Backup to join the Circle; used by CKKS; KeychainCircle.framework; command line tools: tpctl, otctl (Octagon trust is newer?)
CKKS CloudKit Key Sync, end-to-end secure syncing for credentials, seeded by Circle, transferred items stored ephemerally using OTR protocol; currently includes ApplePay, AutoUnlock, CreditCards, DevicePairing, Engram, Health, Home, Manatee, SOS, WiFi and other keys; launchd service: com.apple.secd; command line tool: ckksctl
Classroom launchd service: com.apple.studentd
Chamois Stage Manager
CHIP Connected Home over IP; Matter; integrated into HomeKit, can use Thread as transport layer; HomeKitMatter.framework, CoreThread.framework; launchd services: com.apple.threadradiod, com.apple.ThreadCommissionerService
Circle cryptographic primitive to exchange public keys of trusted devices of a user, signed by Circle peers; iCloud identity added as additional Circle peer, private key synced across all trusted devices, new devices can pull this key from Secure Backup to join the Circle; per-device Circles stored in CKKS for two-factor accounts (Octagon); KeychainCircle.framework; command line tools: otctl (Octagon)
CKKS CloudKit Key Sync, end-to-end secure syncing for credentials, seeded by Circle; currently includes ApplePay, AutoUnlock, CreditCards, DevicePairing, Engram, Health, Home, Manatee, SOS, WiFi and other keys; launchd service: com.apple.secd; command line tool: ckksctl
Clarity customizable accessibility mode for simplified UI; ClarityFoundation.framework
Classroom school teachers can create assignments for student iPads and track progress in Schoolwork app; ClassKit.framework; launchd service: com.apple.studentd
Cloud Pairing part of Alloy, Bluetooth out-of-band pairing over iCloud for Continuity; launchd service: com.apple.BTServer.cloudpairing (cloudpaird)
CMAS Commerial Mobile Alert System, now known as Wireless Emergency Alerts (WEA)
Commpage user-mapped kernel data, like vdso/vsyscall on Linux; mapped at 0x7fffffe00000
Communications Filter recipient blocking for iMessage, FaceTime, Mail; launchd service: com.apple.cmfsyncagent
Companion iPhone that is paired with Watch; communication uses Alloy over IPsec over Bluetooth
Continuity umbrella term for Handoff, Sidecar, SMS relay, Universal Clipboard, Watch unlock, WiFi call relay and others; SMS relay works by proxying to iMessage, other services use Alloy
Companion iPhone that is linked with Watch, Mac, or Apple TV; communication with Watch uses Alloy over IPsec over Bluetooth, AWDL on demand; launchd service: com.apple.companiond; Bonjour service: _companion-link._tcp
Contact Key Verification code for manual verification of iMessage keys; code identifies a long-lived account key stored in iCloud Keychain, which signs all ESS device keys
Continuity umbrella term for Handoff, Sidecar, iPhone Mirroring, SMS relay, Universal Clipboard, Watch unlock, WiFi call relay and others; SMS relay works by proxying to iMessage, other services use Alloy for signalling and AWDL for payload; /System/Applications/iPhone Mirroring.app, ScreenContinuityServices.framework
Control Center icons in menu/status bar and Bento Box controls UI, gradually replaces SystemUIServer on macOS; handles incoming AirPlay content; launchd services: com.apple.controlcenter, com.apple.SystemUIServer.agent
CPML CorePrediction Machine Learning; CPMLBestShim.framework
CRD Conference Room Display; Apple TV mode
Cryptex Cryptographically sealed Extension of SSV, mount-invisible extension of the root volume, allows lightweight updates as part of Rapid Security Response; /System/Cryptexes (mountpoint), /System/Volumes/Preboot/*/cryptex1/current/*.dmg (disk images)
CSR Configurable Security Restrictions; XNU subsystem that is the basis for SIP
CTK Crypto Token Kit; smart card management, also for the Secure Element on iOS? launchd service: com.apple.ctkd; command line tool: sc_auth
CTS Centralized Task Scheduling; execution of DAS tasks; /System/Library/UserEventPlugins/com.apple.cts.plugin
CVMS Core VM Server/Service? compilation of GPU shaders; launchd service: com.apple.cvmsServ
DAAP Digital Audio Access Protocol; used by Home Sharing (with Rapport token) and by the Remote app to control Apple TV (with pairing token); payload unencrypted; DAAPKit.framework; Bonjour services: _atc._tcp, _home-sharing._tcp, _mediaremotetv._tcp, _touch-able._tcp
Daily Briefing Siri giving an overview of information for the day; SiriDailyBriefingInternal.framework
DART DMA Address Relocation Table; IOMMU implementation in Apple silicon, positioned in front of peripheral devices, offers sub-page protection; SART: streaming variant for high-throughput devices (like NVMe)
DART DMA Address Relocation Table; IOMMU implementation in Apple silicon, positioned in front of every DMA-capable co-processor and peripheral, offers sub-page protection; SART: streaming variant for high-throughput devices (like NVMe)
Darwin Directory static store for users and groups, saves Open Directory interaction for the local case? /usr/lib/system/libsystem_darwindirectory.dylib, /System/Library/DarwinDirectory, /private/var/db/DarwinDirectory; command line tool: dddiagnose
DAS Duet Activity Scheduler; scheduling policy engine behind NSBackgroundActivityScheduler and XPC activities; /System/Library/DuetActivityScheduler; launchd service: com.apple.dasd
Data Detectors text analysis to highlight phone numbers, street addresses, and the like; DataDetectors.framework
Data Vault directories with the UF_DATAVAULT special flag; CSR limits access to one application
DAV Distributed Authoring and Versioning; network protocol on top of HTTP for syncing calendars (CalDAV), contacts (CardDAV), and formerly also bookmarks (BookmarkDAV)
DCP Display Co-Processor
DDE Device Discovery Extension; detects devices on local network without app access to local network; DeviceDiscoveryExtension.framework, DeviceDiscoveryUICore.framework; extension point: com.apple.discovery-extension
DEP Device Enrollment Program; devices check in with Apple during Setup Assistant to query for their enrollment status, retrieve MDM server URL to fetch initial configuration profile
Developer Mode enables launching of self-compiled apps in iOS, rough equivalent to System Policy; command line tool: devmodectl
DFR Dynamic Function Row?, TouchBar; /System/Library/CoreServices/ControlStrip.app; DFRFoundation.framework
DFU Device Firmware Update; special boot mode where iOS has not booted and the system can be installed over the Lightning connection
Differential Privacy crowdsourcing without user tracking; privacy budget for management of anonymity set; used for keyboard words, emoji, Spotlight searches, Parsec deep links, HealthKit usage, Safari telemetry; /System/Library/DifferentialPrivacy; stored in /var/db/DifferentialPrivacy; launchd service: com.apple.dprivacyd
Digital Separation safety check feature to inhibit sharing relationships; DigitalSeparation.framework
DMC Device Management Client; part of MDM; DMCUtilities.framework
DMC Disk Mount Conditioner; simulates slow IO devices; command line tool: dmc
DND Do Not Disturb
Domain Association signed files in .well-known directory on websites; equivalent to Entitlements for websites
Dose ambient sound level checking on Watch; /Applications/Dose.app
DSID Destination Signaling Identifier, unique ID for IDS login on a specific device
DTrace system-wide tracing infrastructure, command line tools: dtrace, *.d, dappprof, dapptrace, dtruss, errinfo, execsnoop, fddist, fs_usage, imptrace, iopattern, iopending, iosnoop, iotop, lastwords, latency, opensnoop, plockstat, rwsnoop, sampleproc, sc_usage, topsyscall, topsysproc
Duet telemetry collection engine for system and user events, forecasting by machine learning, backend for DAS, Proactive, Relevance, Screen Time, thermal and battery management; /System/Library/DuetKnowledgeBase; CoreDuet.framework, CoreKnowledge.framework, CorePrediction.framework; launchd services: com.apple.coreduetd, com.apple.knowledge-agent
Dyld Shared Cache dynamic linker cache, stores all system libraries in prelinked form, original library files are removed; /System/Library/dyld; command line tool: update_dyld_shared_cache
Duet telemetry collection engine for system and user events, forecasting by machine learning, backend for DAS, Proactive, Relevance, Screen Time, thermal and battery management; /System/Library/DuetKnowledgeBase, /System/Library/DuetExpertCenter; CoreDuet.framework, CoreKnowledge.framework, CorePrediction.framework, CascadeEngine.framework (link to Biome); launchd services: com.apple.coreduetd, com.apple.duetexpertd, com.apple.knowledge-agent, com.apple.ospredictiond
Dyld Shared Cache dynamic linker cache, stores all system libraries in prelinked form, original library files are removed; /System/Volumes/Preboot/Cryptexes/OS/System/Library/dyld; command line tools: dyld_info, dyld_usage, update_dyld_shared_cache
EAS Exchange Active Sync; network protocol for accessing Microsoft Exchange servers
EDR Extended Dynamic Range; rendering with transfer function extending beyond sRGB white; implemented natively on XDR displays and by backlight modulation on others; HDRProcessing.framework
Energy Impact unitless metric for per-application energy consumption, machine-specific coefficients; /usr/share/pmenergy, /usr/share/kpep; launchd services: com.apple.sysmond, com.apple.thermald; command line tool: powermetrics
Energy Impact unitless metric for per-application energy consumption, machine-specific coefficients; /usr/share/pmenergy, launchd services: com.apple.sysmond, com.apple.thermald; command line tool: powermetrics
Engram Messages in iCloud; devices store received iMessages in CloudKit; Engram.framework
Entitlements capability-like attributes bound to executables by code signing; some entitlements like App Sandbox restrict ambient authority, some gradually relieve those restrictions (using Seatbelt), some services or system calls grant privilege based on caller entitlements
ESS IDS user directory, public key distribution for iMessage and CloudKit sharing, uses Transparency; server: *.ess.apple.com; launchd service: com.apple.identityservicesd
Event Monitor simple rules engine for running commands on various systen events; apparently not used by default; /etc/emond.d, /var/db/emondClients; launchd service: com.apple.emond
Exclave user-level portions of kernel or SEP services, used for paravirtualized access by VMs; /usr/libexec/init_exclavekit
Eye Relief screen distance warning for handheld devices; /Applications/EyeReliefUI.app
FaceTime video calls, employs the ICE (establishing peer-to-peer connection), STUN (session credential exchange) and SRTP (encrypted media streaming) protocols; FTServices.framework; launchd services: com.apple.videoconference.camera (avconferenced)
FairPlay DRM system used by app and media stores; CoreADI.framework, CoreFP.framework, CoreLSKD.framework; launchd services: com.apple.adid, com.apple.fairplayd (invoked by kernel through host special port 17), com.apple.lskdd; credentials stored in /var/db/fpsd
Family Circle Family Sharing; launchd services: com.apple.familycircled, com.apple.askpermissiond
FDE Full Disk Encryption, FileVault; command line tool: fdesetup, sysadminctl
FDR Factory Data/Device Reset? ensures that no downgrades are performed? servers: skl.apple.com, gg.apple.com; /System/Library/FDR
Feldspar Apple News; Silex.framework
FiDES Fi? Distributed Evaluation Service? aggregates Differential Privacy data for unlinkability? maybe private federated learning? used for emoji, Suggestions, Dictation; /System/Library/DistributedEvaluation; DistributedEvaluation.framework; server: fides-pol.apple.com
Find My … location sharing by explicitly querying devices remotely or collateral beacon detection using Search Party; FMCore.framework, FMF.framework; launchd service: com.apple.icloud.fmfd (find my friends)
FiDES Fi? Distributed Evaluation Service? aggregates Differential Privacy data for unlinkability? used for emoji, Suggestions, Dictation; /System/Library/DistributedEvaluation; DistributedEvaluation.framework, FedStats.framework (private federated learning?); server: fides-pol.apple.com
File Provider infrastructure and extension system for syncing with cloud providers; placeholder files based on SF_DATALESS attribute in APFS; FileProvider.framework; locally stored in ~/Library/CloudStorage; command line tool: fileproviderctl
Find My location sharing by explicitly querying devices remotely or collateral beacon detection using Search Party; FMCore.framework, FMF.framework; launchd service: com.apple.icloud.fmfd (find my friends)
Firmlink bi-directional non-symbolic link between the read-only system volume and the data volume, additional symlinks and mountpoints in the root directory are virtually allocated; /usr/share/firmlinks, /etc/synthetic.conf
Focus restriction modes for notification presentation; Focus.framework, DoNotDisturb.framework; local settings in ~/Library/DoNotDisturb
Focus restriction modes for notification presentation; focus filters for in-app display restrictions, communicated by Intents; Focus.framework, DoNotDisturb.framework; local settings in ~/Library/DoNotDisturb
FollowUp user interaction for Secure Backup wrapping with device passcode, CoreFollowUp.framework; launchd service: com.apple.followupd
FoundationDB fundamental iCloud storage database, marketed as CloudKit, separated into containers; records, blobs, and large asset storage with MMCS, server-side continuous queries can trigger push notifications, user management by IDS, sharing between users; PCS keys used for hierarchical zone, record, and asset encryption; CloudKitDaemon.framework; launchd service: com.apple.cloudd; locally stored in ~/Library/Caches/CloudKit, ~/Library/Containers/*/Data/CloudKit; command line tool: cktool
FPR Fast Permission Restrictions; Apple CPU registers to downgrade (old APRRs do bitmasking) or remap (SPRRs since M1) actual permissions of memory pages per thread; used for JIT protection and by AMFI to freeze user code after checking
FUD Firmware Update Daemon; /var/db/fud; launchd service: com.apple.MobileAccessoryUpdater
FoundationDB fundamental iCloud storage database, marketed as CloudKit, separated into containers; records, blobs, and large asset storage with MMCS, server-side continuous queries can trigger push notifications, user management by IDS, sharing between users by GroupKit; PCS keys used for hierarchical zone, record, and asset encryption; CloudKitDaemon.framework; launchd service: com.apple.cloudd; locally stored in ~/Library/Caches/CloudKit, ~/Library/Containers/*/Data/CloudKit; command line tool: cktool
FPR Fast Permission Restrictions; Apple CPU registers to downgrade (old APRRs do bitmasking) or remap (SPRRs since M1) actual permissions of memory pages (the CTRR region) per thread; used for JIT protection and by AMFI to freeze user code after checking
FSKit user space file system support; kernel stub file system is /System/Library/Extensions/lifs.kext; file systems are in /System/Library/ExtensionKit/Extensions/com.apple.fskit.*; launchd service: com.apple.filesystems.fskitd, com.apple.filesystems.doubleagentd (handling of Apple double files in user space); extension point: com.apple.fskit.fsmodule
FUD Firmware Update Daemon; see TSS, UARP; launchd service: com.apple.accessoryupdaterd
Game Mode auto-activates when games are shown full screen, throttles background work, lowers audio and input latency; launchd service: com.apple.gamepolicyd
GID group ID key, shared across all devices of the same SoC generation, derived keys are used to prove device type over the network, only accessible by SEP
Gizmo Apple Watch; watch settings managed by Companion; /Applications/Bridge.app, /System/Library/BridgeManifests
Gizmo Apple Watch; watch settings managed by Companion iPhone; /Applications/Bridge.app, /System/Library/BridgeManifests
Greymatter Apple Intelligence; on-device language and diffusion models, larger server-based models in PCC; AFM refined for specific tasks (queries, summarization, categorization) by adapters (parameter for inserted network modules); grounded with context from Biome and intelligence stores; ~/Library/IntelligencePlatform; launchd service: com.apple.modelmanagerd (model residency management); /System/Library/ModelManager/Policy.plist; /Applications/Tamale.app (Camera Control integration); command line tool: csfdiagnose (cloud subscription features), modelmanagerdump
Group Activities SharePlay; sharing of media content and programmatic state over FaceTime calls; GroupActivities.framework, CopresenceCore.framework; launchd service: com.apple.telephonyutilities.callservicesd
GroupKit groups of IDS users with shared CloudKit (PCS) access; GroupKit.framework
GSS Generic Security Service; part of Kerberos; GSS.framework; launchd service: com.apple.gssd (invoked by kernel through host special port 19); command line tool: gsstool
GXF Guarded Execution Feature/Fault, additional exception levels on Apple Silicon, lateral to the usual exception levels; page tables remain the same, but interpretation of permission bits changes by way of FPR, genter and gexit instructions; implements lightweight intra-address-space protection contexts
HAP Home Automation Protocol; CoreHAP.framework
HDA High Definition Audio; HDAInterface.framework
HDI Hard Disk Image; command line tool: hdiutil
HeadBoard derivative of SpringBoard for tvOS home screen; /Applications/HeadBoard.app, /Applications/PineBoard.app
Health Balance vitals app on Watch; /Applications/NanoHealthBalance.app
HLS HTTP Live Streaming
HomeEnergy HomeKit management for grid energy supply; EnergyKit.framework
HSA Hardware Security Architecture; version 1 used for two-step verification, SOS with iCSC; version 2 for two-factor authentication, CKKS and Secure Backup with iCDP
HSM Hardware Security Module; HSM fleet runs escrow service for Secure Backup; public keys for authenticating the HSM services in /System/Library/Security/Certificates.bundle/Contents/Resources/AppleESCertificates.plist
Hyperion iCloud Photos, uses CloudKit; launchd service: com.apple.cloudphotod; command line tool: cpldiagnose
HSM Hardware Security Module; HSM fleet runs escrow service for Secure Backup
Hyperion iCloud Photos, uses CloudKit; launchd service: com.apple.cloudphotod
IAP iPod Accessory Protocol; IAP.framework
iBoot boot loader stage after boot ROM or UEFI (macOS on Intel); intermediate Low-Level Bootloader (LLB); DFU mode is implemented here; /System/Library/CoreServices/boot.efi
iCDP iCloud Data Protection, codename for a set of enhancements to iCloud privacy: device passcodes used as iCSC for Secure Backup, root keys for CKKS-enabled services only synced between devices and not stored at Apple; launchd service: com.apple.cdpd
iCloud umbrella term for a conglomerate of services, consists of FoundationDB containers with PCS views for key management, supported by CKKS; uses IDS and APNS; some services under the iCloud name are actually served by AMS, IMAP, or DAV
iCSC iCloud Security Code, credential wrapping for Secure Backup, previously used a separate code, with HSA2/iCDP uses device passcodes
IDAM Inter-Device Audio and MIDI; audio connection between devices
IDS Identity Service, also IDMS, Apple ID identity management for all of Apples online services; APNS topics for signaling and messaging, see also Alloy, ESS, FaceTime, iMessage; authentication to services with Kerberos
IDS Identity Directory Service, also IDMS, Apple Account identity management for all of Apples online services; APNS topics for signaling and messaging, see also Alloy, ESS, FaceTime, iMessage; authentication to services with Kerberos
IDV Identity Verification? Touch ID and Face ID; /System/Library/AccessibilityBundles/CoreIDVUI.axbundle
IM Instant Messaging; usually means iMessage and FaceTime
IMG4 boot files (Mach-O binaries or configuration data) with ASN.1 signature, contains RemotePolicy certificate constraints to restrict Boot Policy evaluation
Intent use-case-driven interaction with 3rd-party apps from a host app; used for Siri, Maps, Widgets (configuration); extension points: com.apple.intents-service, com.apple.intents-ui-service
Intent semantic interaction between app and system (or another app); used for Siri, Shortcuts, Maps (contextual suggestion), Widgets (configuration); definition by file or programmatically using AppIntents.framework; command line tool: appintentsmetadataprocessor (Xcode extracts Intent definition at compile time); extension points: com.apple.intents-service, com.apple.intents-ui-service
IOKit device driver subsystem for in-kernel and DriverKit drivers, command line tool: ioreg
Ironwood dictation, customized on server with selected user data (contacts, app names, music titles, HomeKit names, Siri Shortcut phrases), not tied to Apple ID; SpeechRecognitionCore.framework; server: guzzoni.apple.com
Ironwood dictation, customized on server with selected user data (contacts, app names, music titles, HomeKit names, Siri Shortcut phrases), not tied to Apple Account; SpeechRecognitionCore.framework, ASRBridge.framework; server: guzzoni.apple.com
ISP Image Signal Processor; camera imaging circuit in iPhones
ITML iTunes Markup Language; metdata tagging for media services; ITMLKit.framework
ITP Intelligent Tracking Prevention, cross-site tracking defenses in Safari, statistics and user interaction classify sites, cookies are partitioned and access is restricted
JARVIS Just A Rather Very Intelligent Scheduler, Mesos cluster manager for Siri, iCloud, AMS
Jellyfish Animoji
Jellyfish Animoji; /Applications/Jellyfish.app
Jetsam reclaiming of purgeable memory and termination of apps during memory pressure
JSC JavaScript Core; JavaScriptCore.framework; command line tool: jsc
Kalamata codename for the transition from x86 to ARM-based Apple Silicon
Kerberos single-sign-on mechanism; Heimdal.framework; command line tools: kinit, ktutil
Kext kernel extension mechanism, loaded at boot time as part of a Kext Collection; /Library/Extensions, /Library/StagedExtensions (for user approval), /System/Library/Extensions; command line tool: kextutil (manages deprecated runtime loading)
Kext Collection prelinked sets of kernel extensions; /System/Library/KernelCollections (for boot and system kexts), /Library/KernelCollections (for auxiliary third-party kexts); the latter is only loaded at a lower-security Boot Policy; launchd service: com.apple.kernelmanagerd (invoked by kernel through host special port 15); command line tool: kmutil
Keybag storage of protection class keys for Keychain and filesystem, protected by SEP using SKP; stored in user.kb; launchd services: com.apple.mobile.keybagd, com.apple.securityd_service, com.apple.secd
Keybag storage of protection class keys for Keychain and filesystem, protected by SEP using SKP; stored in user.kb; launchd services: com.apple.mobile.keybagd, com.apple.secd
Keychain storage for credentials; launchd service: com.apple.securityd; command line tools: certtool, security, systemkeychain
KIP Kernel Integrity Protection, locking of physical memory pages to prevent changes to kernel
Launch Services management for application launches, association of UTIs to apps, uses Spotlight to update cached info; launchd services: com.apple.coreservices.launchservicesd, com.apple.lsd; CoreServices.framework/LaunchServices.framework; command line tools: lsappinfo, lsregister
Live Files user mode filesystems, currently FAT, ExFAT, NTFS on external storage; UserFS.framework, UVFSXPCService.framework; launchd service: com.apple.filesystems.userfsd
Liverpool PCS codename for CloudKit
LKDC Local Key Distribution Center, Kerberos on client machines
LSM Latent Semantic Mapping, text analysis, used for spam filtering, command line tool: lsm
Mac Buddy historic name for Setup Assistant
MAC Policy Mandatory Access Control subsystem in XNU, based on TrustedBSD, implements policy hooks for restricted kernel operations; current policies: AMFI, Seatbelt, Quarantine, CSR
Machine Learning Vision.framework, Espresso.framework, Futhark.framework, PhotoAnalysis.framework
Machine Learning Vision.framework, Espresso.framework, Futhark.framework, PhotoAnalysis.framework; used for Live Text and Visual Lookup; launchd service: com.apple.mediaanalysisd
Madrid iMessage; /System/Library/Messages
Manatee PCS key for some CloudKit containers are synced via CKKS, so data is unreadable to Apple (credential management codenames: Plesio, Stingray, Cuttlefish)
Mandrake emergency siren on Apple Watch Ultra; /Applications/Mandrake.app
Mangrove transfering UI tiles over XPC; Mangrove.framework, IOSurface.framework
Marco Marco.framework, something about IDS and communication (iMessage, Calls), logging?
Marklar codename from the PowerPC era for the port to x86, served the transition to Intel CPUs
MARRS Multimodal Reference Resolution; Marrs.framework
Marzipan Catalyst; port of iOS frameworks to macOS, Catalyst apps are iOS apps with additional API to adapt macOS UI idioms; /System/iOSSupport; integration using UIKit system process; launchd service: com.apple.uikitsystemapp; input remapping by /Library/Apple/Library/Bundles/InputAlternatives.bundle
MCX Managed Client for OS X, preference management for settings from configuration profiles, /Library/Managed Preferences, command line tools: mcxquery, mcxrefresh
MDM Mobile Device Management; server software to manage fleets of iOS and macOS devices; uses configuration profiles to manage preferences; ConfigurationProfiles.framework
MDS Module Directory Services, ancient part of the old security APIs (CSDA, CSSM)
Memory Debugging uses Taskport; command line tools: heap, leaks, malloc_history, stringdups, vmmap
Mesa Touch ID; /Library/Catacomb; /var/db/bkad.db
Mesa Touch ID; /Library/Catacomb
Metadata Spotlight; file indexing on macOS; CoreServices.framework/Metadata.framework, CoreServices.framework/SearchKit.framework; stored in .Spotlight-V100; launchd service: com.apple.metadata.mds; command line tools: mddiagnose, mdfind, mdimport, mdls, mdutil; in addition to auto-indexing, apps can explicitly register searchable items; CoreSpotlight.framework; launchd service: com.apple.corespotlightd
Micro Location positioning service on macOS (because there is no GPS?); MicroLocation.framework; launchd service: com.apple.milod
MLHost background machine learning service; launchd service: com.apple.mlhostd; /System/Library/MLHost; DeepThought.framework, LighthouseBackground.framework, LighthouseBitacoraFramework.framework, Dendrite.framework
MMCS MobileMe Chunk Storage, used by iCloud, splits blobs into chunks and stores them at Apple/AWS/GCP with convergent encryption (content hash as key); MMCS.framework
Mobile prefix for iOS
Mobile Assets demand-downloaded system components like fonts, dictionaries, linguistic data; stored in /System/Library/Assets; launchd services: com.apple.languageassetd (language-dependent assets), com.apple.mobileassetd; server: mesu.apple.com
Mobile Device connectivity to iOS devices over USB or WiFi (AirTrafficHost) for syning, development, and debugging; MobileDevice.framework; launchd service: com.apple.usbmuxd; Bonjour service: _apple-mobdev2._tcp
MOC Managed Object Context; Core Data object space
Mondrian photo collage arrangement in Photos.app; Mondrian.framework
MRT Malware Removal Tool; /Library/Apple/System/Library/CoreServices/MRT.app
MRT Malware Removal Tool; /Library/Apple/System/Library/CoreServices/MRT.app; superseded by XProtect
Multipeer Connectivity ad-hoc networking; Bonjour for discovery; WiFi, AWDL, Bluetooth, or Ethernet as transport; optional encryption and certificate-based authentication; MultipeerConnectivity.framework
Nano prefix for watchOS
Neural Engine hardware accelerator for neural network operations; ANECompiler.framework, ANEServices.framework; launchd service: com.apple.aned
Nearby Interaction proximity-based interaction between devices; proximity measured using ultra wideband or derived from other technologies; used for Universal Control, tapping phones for AirDrop; NearbyInteraction.framework, Proximity.framework; launchd services: com.apple.aonsensed (always-on sense daemon), com.apple.nearbyd
Nebula sleep apnea detection on watchOS; BreathingAlgorithms.framework
Newton fall detection on watchOS
NLP Natural Language Processing; NLP.framework; related to mecabra libraries, a linguistic engine for Chinese and Japanese; /usr/share/mecabra, /usr/share/tokenizer
Notarization app security scan by Apple; cryptographic proof stapled to code signature, tested at launch by System Policy; for non-notarized apps sends code hash to Apple; command line tools: altool, notarytool, stapler
Notarization app security scan by Apple; cryptographic proof stapled to code signature, tested at launch by System Policy; for non-notarized apps sends code hash to Apple; command line tools: notarytool, altool, stapler
Noticeboard User Notifications for Software Update and App Store, Noticeboard.framework; launchd services: com.apple.noticeboard.state (nbstated), com.apple.noticeboard.agent (nbagent)
Notifications system notification bus, unrelated to the local/remote push notifications; launchd service: com.apple.notifyd, com.apple.kuncd (invoked by kernel through host special port 10); command line tool: notifyutil; complemented by framework-level notification system (CFNotification, NSNotification); launchd services: com.apple.distnoted.xpc.daemon, com.apple.distnoted.xpc.agent
NSP Network Service Proxy; per-app VPN and proxy settings, implements Private Relay; launchd service: com.apple.networkserviceproxy
OAH Rosetta; /usr/libexec/rosetta
OAH Rosetta; ahead-of-time compiler for Intel code on Apple Silicon, usable from Linux VMs by way of a custom binformat; /usr/libexec/rosetta; launchd service: com.apple.oahd
ODR On-Demand Resources; loaded from App Store; launchd service: com.apple.appstored
Omni Search fuzzy semantic search with results recognized in images; OmniSearch.framework
Onboarding data protection splash screen shown by service-connected apps; /System/Library/OnBoardingBundles; OnBoardingKit.framework
Open Directory directory service for user, group, and machine management; plugin-based to use different backend stores (LDAP, Active Directory), local accounts in /private/var/db/dslocal; launchd service: com.apple.opendirectoryd; command line tools: dscacheutil, dscl, dsconfigad, dsconfigldap, dseditgroup, dsenableroot, dserr, dsexport, dsimport, dsmemberutil, odutil
Open Directory directory service for user, group, and machine management; plugin-based to use different backend stores (LDAP, Active Directory), local accounts in /private/var/db/dslocal, populated from /System/Library/DirectoryServices/DefaultLocalDB; launchd service: com.apple.opendirectoryd; command line tools: dscacheutil, dscl, dsconfigad, dsconfigldap, dseditgroup, dsenableroot, dserr, dsexport, dsimport, dsmemberutil, odutil
OpenBSM Open Basic Security Module; deprecated security audit subsystem; /etc/security, /var/audit; launchd service: com.apple.auditd; command line tool: audit
Opus create slide shows from photos; Slideshows.framework
OSA Open Scripting Architecture; scripting of applications from different fontend languages (currently AppleScript and JavaScript); backed by Apple Events; command line tools: osacompile, osadecompile, osalang, osascript, sdef, sdp
OTUT One-Time Unlock Token; security mechanism to allow keybag unwrapping after updates
PAC Pointer Authentication Codes; pointers signed in unused bits to prevent ROP attacks
Packages unit of software installation; command line tools: pkgutil, installer, softwareupdate; launchd services: com.apple.softwareupdated, com.apple.bootinstalld, com.apple.installd, com.apple.system_installd, com.apple.uninstalld; /var/db/softwareupdate, /Library/Apple/System/Library/Receipts (system), /System/Library/Receipts (read-only), /private/var/db/receipts (App Store)
Parsec Spotlight web results and searching of crowdsourced User Activity deep links; server: *.smoot.apple.com; launchd services: com.apple.parsecd, com.apple.parsec-fbf (Feedback Flush to Differential Privacy)
Packet Filter network traffic filtering subsystem from OpenBSD; command line tool: pfctl
Parsec Spotlight web results and searching of crowdsourced Intent deep links; server: *.smoot.apple.com; launchd services: com.apple.parsecd, com.apple.parsec-fbf (Feedback Flush to Differential Privacy); telemetry collection with Poirot: PoirotSQLite.framework, PoirotUDFs.framework, SearchOnDeviceAnalytics.framework
Party Studio Karaoke mode on tvOS, where video from a paired phone is shown with effects; /System/Library/PrivateFrameworks/PartyStudio.*
Passkey keypair used for authentication instead of password, synced via SOS, implements WebAuthn standard; keys can be used to login on separate device via QR code and Bluetooth proximity proof; AuthenticationServices.framework
Password Breach monitoring of Keychain passwords against a breach database; round-robin matching in fixed-size batches, local match against common leaks, remote match using hash prefix; launchd service: com.apple.Safari.passwordbreachd
Pasteboard storage for cut, copy, and paste; type of content remembered as UTI; launchd service: com.apple.pboard; command line tools: pbcopy, pbpaste
PCS Protected Cloud Storage; key management for separate iCloud storage compartments (PCS calls them views), each can contain FoundationDB plus bulk data stored by MMCS; see also iCDP, CKKS, Manatee; ProtectedCloudStorage.framework; /System/Library/Preferences/ProtectedCloudStorage; command line tool: pcsstatus
PAT Private Access Tokens; blind challenge-response authentication; Apple server attests user validity to token issuer, issuer performs blind signature, websites receiving the token cannot identify user; used for Private Relay, can replace CAPTCHAs
PCC Private Cloud Compute; server-based AFM for AI, running on Apple Silicon managed by SEP; stateless computation, PAT to authorize user, Attestation of remote code by device, measurements published in Transparency; ~/Library/PrivateCloudCompute; launchd services: com.apple.privatecloudcomputed, com.apple.swtransparencyd
PCS Protected Cloud Storage; key management for separate iCloud storage compartments (PCS calls them views), each can contain FoundationDB plus bulk data stored by MMCS; see also iCDP, CKKS, GroupKit, Manatee; ProtectedCloudStorage.framework; /System/Library/Preferences/ProtectedCloudStorage; command line tool: pcsstatus
PCSC Personal Computer Smart Card; PCSC.framework, uses CTK
PDE Print Dialog Extension; old name, not a proper Extension
Pegasus picture-in-picture video playback; Pegasus.framework (iOS), PIP.framework (macOS)
PEC/PIR Private Encrypted Compute and Private Information Retrieval; used for parental controls for media and web; CipherML.framework; launchd service: com.apple.ciphermld
Pegasus meaning 1: picture-in-picture video playback; Pegasus.framework (iOS), PIP.framework (macOS); meaning 2: online search query engine for visual lookup; PegasusKit.framework
People contacts with Apple Accounts within Group Activities and Shared With You
Pepper UI elements for Watch home screen and Chat, like Quickboard (canned replies), Animoji; PepperUICore.framework
Persona separation of sub-user-identities, like when using a private and managed Apple account; PersonaKit.framework; ~/Library/Personas; /System/Library/UserManagement; command line tool: umtool
PHASE spatial audio processing; PHASE.framework
PHASE Physical Audio Spatialization Engine; 3D sound rendering engine; Apple devices map audio sources (even mono and stereo) to virtual speakers in a 3D sound stage, which is simulated by the physical speakers via a head-related transfer function; PHASE.framework
Piano Mover Mail Drop; bulk mail attachments transfered over PCS; not to be confused with storage for iMessage attachments, which uses a CloudKit container
Plugin Extensions, XPC services bundled with apps or frameworks, discovery by Launch Services; launchd service: com.apple.pluginkit.pkd; command line tool: pluginkit
Plugin Extensions, XPC services bundled with apps or frameworks, discovery by Launch Services; extension points listed in /System/Library/ExtensionKit/ExtensionPoints; launchd service: com.apple.pluginkit.pkd; command line tool: pluginkit
PMC Performance Monitoring Counters; Recount.framework; /usr/share/kpep
PMP Port Mapping Protocol; Apple alternative to UPnP, Bonjour service: _acp-sync._tcp
Poster iPhone lock screen; PosterBoard.framework, PosterKit.framework; /Library/Wallpaper
PowerUI battery management like smart charge and power save, learns from Duet and other data; PowerUI.framework; /var/db/PowerUI; launchd service: com.apple.PowerUIAgent
Preferences storage for user-configurable settings; launchd services: com.apple.cfprefsd.xpc.daemon, com.apple.cfprefsd.xpc.agent; stored in Library/Preferences, command line tool: defaults; interaction with Synced Defaults per /System/Library/DefaultsConfigurations
Private Relay two-hop onion routing with one entry and one exit node; Apple operates entry, third-party services operate exit nodes; approximate IP geolocation via Waldo
Proactive umbrella term for suggestions and completions based on Duet forecasting and User Activity context, also marketed as Siri features; PersonalizationPortrait.framework
Preview Shell skeleton for on-device UI previews during development; /System/Library/CoreServices/PreviewShell.app; PreviewShellKit.framework, XOJIT.framework (code live patching)
Private Relay two-hop onion routing with one entry and one exit node; Apple operates entry, third-party services operate exit nodes; QUIC for payload, ODoH for DNS, approximate IP geolocation via Waldo, authentication via PAT
Proactive umbrella term for suggestions, completions, and summarizations based on Duet forecasting, Biome, and Intent context; PersonalizationPortrait.framework, ProactiveMagicalMoments.framework, ProactiveSummarization.framework
Provenance per-file origin tracking, extended attribute com.apple.provenance stores ID into /var/db/SystemPolicyConfiguration/ExecPolicy
QoS Classes inheritable property for Activities; semantic priorities, influences scheduling parameters; initially set at user-level, priority inheritance within GCD queues and across XPC in kernel?
Quagga framework for QR and barcode decoding; Quagga.framework
Quick Action extension type for quick interaction with foreign content within a host app; extension points: com.apple.services, com.apple.ui-services
Quick Look file preview and thumbnail generation; comand line tool: qlmanage
RAOP Remote Audio Output Protocol, AirPlay; Bonjour service: _raop._tcp
Rapport device pairing by proximity using Alloy, with PIN entry, or using iCloud; once paired, devices can access services; used for HomeKit, HomePod, AirPlay, Home Sharing, SideCar; Rapport.framework; launchd service: com.apple.rapportd; Bonjour service: _companion-link._tcp
Rapport device pairing by proximity using Alloy, with PIN entry, or using iCloud; once paired, devices can access services; used for HomeKit, HomePod, AirPlay, Home Sharing, SideCar; Rapport.framework, ProximityAppleIDSetup.framework; launchd service: com.apple.rapportd
RCS Rich Communication Services; messaging service in mobile networks, successor to SMS; IMRCSTransfer.framework; /System/Library/Messages/PlugIns/RCS.imservice
Recents recently used items (not files) in various applications, synced with Synced Defaults; CoreRecents.framework, /System/Library/Recents; launchd service: com.apple.recentsd
Relevance Engine backend for Siri suggestions (for example of Siri Shortcuts), Widget smart stacks (also Siri watch face); consumes Duet knowledge and app-provided timelines with relevance hints; /System/Library/RelevanceEngine; launchd service: com.apple.relevanced
Relevance Engine backend for Siri suggestions (for example of Siri Shortcuts), Widget smart stacks (also Siri watch face); consumes Duet knowledge and app-provided timelines with relevance hints; /System/Library/RelevanceEngine
Remote Pairing Mobile Device pairing without wired connection; RemotePairingDevice.framework; Bonjour services: _remotepairing._tcp, _remotepairing-manual-pairing._tcp
RemoteXPC connection to a non-SoC-integrated SEP like Bridge; uses HTTP/2 over a network interface, Bridge connected over USB, secured using Attestation; RemoteServiceDiscovery.framework, TrustedAccessory.framework; launchd service: com.apple.remoted, com.apple.tracd; command line tool: remotectl
Replicator notification sync from Companion iPhone, also drives remotely displayed live activities; ReplicatorServices.framework; launchd service: com.apple.replicatord
Revisions document autosave and auto-versioning; stored in .DocumentRevisions-V100; GenerationalStorage.framework; launchd service: com.apple.revisiond
Routine frequently visited locations on iOS, interacts with Duet; launchd service: com.apple.routined
RTC Real-time Telemetry and Crash reporting; RTCReporting.framework; launchd service: com.apple.rtcreportingd
RTKit operating system used on Apple Silicon for firmware of co-processors
RunningBoard runtime management of apps, paradigm: app as service process invoked by system, check-in by frameworks, handles process assertions (frontmost app, see App Nap), memory pressure (see Jetsam) and compute resources (GPU), replacement for TAL?; launchd service: com.apple.runningboardd; /System/Library/LifecyclePolicy, /System/Library/RunningBoard
Safety Monitor Check In; short-term location sharing in iMessage until a destination is reached; /Applications/SafetyMonitorApp.app
SBPL Sandbox Profile Language; a TinyScheme-based embedded DSL for Seatbelt profiles
SCIP System Coprocessor Integrity Protection; like KIP, but for SEP, ISP, Motion coprocessor
Screen Reader VoiceOver and Braille; /System/Library/ScreenReader; ScreenReader.framework
@@ -237,60 +296,78 @@ Search Party portion of Find My service for offline devices; devices emit public
Seatbelt process sandbox by filtering system calls; profiles written in SBPL; /System/Library/Sandbox/Profiles, /usr/share/sandbox; default file access policy asks for TCC confirmation before access to folders with user data (like Documents) is allowed; command line tool: sandbox-exec; launchd service: com.apple.sandboxd (invoked by kernel through host special port 14 for logging)
Secure Backup escrow part of CKKS; escrow key individually wrapped with passcodes of trusted devices, stored in HSM to prevent brute forcing, uses SRP so passcodes are not visible to iCloud, limited number of recovery attempts; protocol called Lakitu, uses FollowUp; launchd service: com.apple.SecureBackupDaemon (com.apple.sbd); CloudServices.framework
SEP Secure Enclave Processor; dedicated ARM core for security services, runs L4/Darbat-based sepOS, inline encryption to DRAM, manages AES keys in storage DMA engine, factory-paired channels to Touch ID/Face ID hardware, Secure Element, Neural Engine; SEP can use but not read UID and GID keys; credential verification performed by hardware lockbox with retry count enforcement
Seymour Apple Fitness+; workout videos integrated with Watch sensors; SeymourCore.framework
Sequoia translation; downloadable language models can run on-device; /Applications/SequoiaTranslator.app, Translation.framework
Seymour Apple Fitness+; workout videos integrated with Watch sensors; SeymourCore.framework, Blackbeard.framework (personalisation and workout programs)
SF Symbols scalable UI symbols; rendered with various color treatments; SFSymbols.framework
Shared File List lists of recently opened files from apps that are stored with Launch Services; command line tool: sfltool; also manages login items and app-installed background daemons
Shared With You collaboration features between apps and iMessage; content shared via iMessage is surfaced in apps (Swift Transferable protocol), content in apps can be collaboratively edited and connected to an iMessage group; collaborations are expressed by keys derived from participant device keys, padded with a number of random keys to prevent tracking of device count, a merkle tree of those keys is used to prove inclusion of a specific device to an app; SharedWithYou.framework
Sharing umbrella term for wireless proximity services: AirDrop, Continuity, Instant Hotspot, WiFi sharing; used by loginwindow for Watch unlock; Sharing.framework; launchd service: com.apple.sharingd; also serves connection sharing and remote disk
Shazam music recognition service; ShazamKit.framework; launchd service: com.apple.shazamd
Shazam audio (especially music) recognition service; ShazamKit.framework; launchd service: com.apple.shazamd; command line tool: shazam
Shoebox Passbook
Sidecar using iPhone/iPad as Mac accessory: camera for photos and scanning, annotations, external display over low-latency WiFi (llw interface) using avconferenced encoding; SidecarCore.framework; launchd services: com.apple.sidecar-display-agent (SidecarDisplayAgent), com.apple.sidecar-relay (SidecarRelay)
Sidecar using iPhone/iPad as Mac accessory: external camera and microphone (ContinuityCapture), camera for photos and scanning (DocumentCamera.framework), iPad as display over low-latency WiFi (llw interface) using avconferenced encoding; /Applications/Sidecar.app; SidecarCore.framework; launchd services: com.apple.sidecar-display-agent (SidecarDisplayAgent), com.apple.sidecar-relay (SidecarRelay)
Signpost telemetry API to report points of interest in code; launchd service: com.apple.signpost.signpost_reporter
Simulator running an iOS/tvOS/watchOS personality on macOS, uses sandboxing and a separate Mach bootstrap namespace for container-like isolation, command line tool: simctl
SIL Secure Indicator Light; microphone and camera indicator on iPads rendered in hardware
Simulator running an iOS/tvOS/watchOS personality on macOS, uses sandboxing and a separate Mach bootstrap namespace for container-like isolation; installable simulators as disk images in /Library/Developer/CoreSimulator/Images; command line tool: simctl
SIP System Integrity Protection or rootless mode; collection of kernel-level security restrictions regarding file system modification, unsigned Kexts, Taskport access, NVRAM access, DTrace; /System/Library/Sandbox/rootless.conf; command line tool: csrutil, rootless-init
Site Association signed files in .well-known directory on websites; equivalent to Entitlements for websites, associates domains with app IDs for Universal Links; command line tool: swcutil
SKP Sealed Key Protection; measurement of system state (boot chain IMG4 manifests, BPR, Boot Policy data, UID key, user passcode) to derive Keybag keys
SKS Secure Key Store; handling of keybag keys within the SEP
SkyLight WindowServer; SkyLight.framework
Skywalk network subsystem in XNU, links together actual technologies (Bluetooth, WiFi, Thunderbolt) and interfaces/tunnels; transacts in nexus (for conduits) and agent (for endpoints) objects; DriverKit network drivers use Skywalk; command line tool: skywalkctl
SLC System-Level Cache, architectural feature of Apple Silicon; cache located within SoC at controllers for external DRAM, serves all compute units and stages transfers between them
Social Gaming Game Center; multiplayer gaming services on top of CloudKit, shared storage and low-latency multicast for multiplayer sessions; launchd service: com.apple.gamed
Sock Puppet Watch interaction that requires Companion device
SOS Secure Object Sync; syncing backend for iCloud Keychain, not to be confused with the emergency call feature; transferred items previously staged in Synced Defaults, now uses CKKS; launchd services: com.apple.secd (access to local keychain), com.apple.security.cloudkeychainproxy3 (connects to Synced Defaults), com.apple.security.keychain-circle-notification
Sock Puppet Watch interaction that requires Companion iPhone
SOS Secure Object Sync; syncing backend for iCloud Keychain, not to be confused with the emergency call feature; transferred items previously staged in Synced Defaults, for two-factor accounts in CKKS; launchd services: com.apple.secd (access to local keychain), com.apple.security.cloudkeychainproxy3 (connects to Synced Defaults), com.apple.security.keychain-circle-notification
SPI System Private Interface; /System/Library/PrivateFrameworks
SpringBoard iOS home screen; like Dock (Launchpad, Mission Control, desktop picture), Control Center, SystemUIServer (menu extras icons), loginwindow (lock screen), and WindowServer (compositor) on macOS; /System/Library/CoreServices/SpringBoard.app, /Applications/PreBoard.app, BaseBoard.framework, FrontBoard.framework, SplashBoard.framework; launchd service: com.apple.backboardd (compositor)
SPRR Shadow Permission Remap Register? feature of Apple Silicon to dynamically reintepret page permissions
SPTM Secure Page Table Monitor; code with higher-than-kernel privileges (Trustzone Monitor?) protects page table modifications; deprivileged Trusted Execution Monitor (TXM) implements policy; successor to FPR/SPRR?
SRP Secure Remote Password; standard cryptographic protocol for proving knowledge of a secret such that attackers cannot brute-force the secret; AppleSRP.framework
SSO Single Sign-On
SSV Signed System Volume, als called Authenticated Root Volume (ARV); macOS boots from blessed read-only APFS snapshot, merkle-tree and root-hash stored in Preboot volume; modifications require disabling root authentication with csrutil from recovery, then the live filesystem can be mounted, modified, and re-blessed; command line tools: apfs_systemsnapshot, bless, csrutil
Stark CarPlay
Stark CarPlay; iPhone provides video feeds for in-car displays; three layers composited by the car: remote UI (from iPhone), punch-through UI (back up camera), local UI (dashboard gauges: assets from iPhone, rendered by car, like Live Activities?), overlay UI (essential indicators); associate apps on iOS: /Applications/AutoSettings.app, /Applications/CarCamera.app, /Applications/Charge.app, /Applications/Climate.app, /Applications/Closures.app, /Applications/Media.app, /Applications/TirePressure.app, /Applications/Trip.app
Stockholm Secure Element in Apple SoCs, a processor running crypto protocols on keys it protects; used for Apple Pay and Car Key; related codenames: Icefall, Warsaw
Storage Management freeing up disk space by managing bulky items; UI in System Information.app; StorageManagement.framework; launchd service: com.apple.diskspaced; extension point: com.apple.storagemanagement; extends Cache Delete service
Suggestions semantic analysis of mails and websites to suggest contacts, calendar events and the like; launchd services: com.apple.suggestd, com.apple.reversetemplated; custom JavaScript parsers in /System/Library/AssetsV2/com_apple_MobileAsset_CoreSuggestions
Symbols debug symbols for backtraces; CoreSymbolication.framework; launchd services: com.apple.coresymbolicationd; command line tools: symbols, symbolscache
Symbols debug symbols for backtraces; CoreSymbolication.framework; launchd services: com.apple.coresymbolicationd; command line tools: atos, symbols, symbolscache
Symptoms network diagnostics; Symptoms.framework; /var/networkd/db/netusage.sqlite; launchd service: com.apple.symptomsd (invoked by kernel through host special port 27)
Synced Defaults simple key-value store for applications, no user control over data; can use iCloud key-value backend (old) or Manatee container (new, marked as com.apple.kvs) as storage; launchd service: com.apple.syncdefaultsd; locally stored in ~/Library/SyncedPreferences
System Configuration SystemConfiguration.framework; launchd service: com.apple.configd; command line tool: scutil
System Extension user-level components formerly in the kernel; currently either a DriverKit, Network, or Endpoint Security extension; /System/DriverKit, /System/Library/DriverExtensions; command line tool: systemextensionsctl; launchd services: com.apple.sysextd, com.apple.nesessionmanager, com.apple.endpointsecurity.endpointsecurityd
System Policy Gatekeeper; policy engine for application launches and kext loading, malware signatures from /Library/Apple/System/Library/CoreServices/XProtect.bundle; /var/db/SystemPolicy; launchd service: com.apple.security.syspolicy (invoked by kernel through host special port 29); command line tool: spctl
System Extension system-wide components formerly implemented as insecure plugins or kexts; current extension types: DriverKit, FSKit, Network, Endpoint Security, Core Media IO; /System/DriverKit, /System/Library/DriverExtensions, /Library/Preferences/com.apple.networkextension.plist; command line tool: systemextensionsctl; launchd services: com.apple.sysextd, com.apple.nesessionmanager, com.apple.endpointsecurity.endpointsecurityd; command line tool: eslogger
System Policy Gatekeeper; policy engine for application launches and kext loading, malware signatures from /Library/Apple/System/Library/CoreServices/XProtect.bundle; /var/db/SystemPolicyConfiguration; launchd service: com.apple.security.syspolicy (invoked by kernel through host special port 29); command line tool: spctl
Tailspin sampling of process stack traces; launchd service: com.apple.tailspind; command line tool: tailspin
TAL Transparent App Lifecycle; process for macOS apps started and stopped independently of the user launching and quitting app; also handles session restore across reboots; ~/Library/Saved Application State; launchd service: com.apple.talagent
Taskport Mach kernel concept for ptrace-like access to task internals; access policy implemented by daemon; launchd service: com.apple.taskgated (invoked by kernel through task special port 9); command line tool: DevToolsSecurity
TCC Transparency, Consent, and Control; user control over app access to privacy-related services (kTCCService*); TCC.framework; launchd services: com.apple.tccd, com.apple.tccd.system; command line tool: tccutil; stored in /Library/Application Support/com.apple.TCC, ~/Library/Application Support/com.apple.TCC, /var/db/locationd (for kTCCServiceLocation)
Template App code-less app-bundle, passed to an actual executable by LauncServices; created when adding websites in Safari to Dock/Springboard; run by /System/Volumes/Preboot/Cryptexes/App/System/Library/CoreServices/Web App.app
Time Machine automatic backup service, command line tools: tmdiagnose, tmutil
Tin Can Walkie Talkie on watchOS
Tin Can Walkie Talkie on watchOS; /Applications/TinCan.app
Tones ringtones; ToneLibrary.framework
Translocation app binary copied on launch to dedicated location; initiated by Launch Services for security (prevents path traversal for apps quarantined by System Policy) or path normalization (iOS apps do not expect to be moved, but can be moved on macOS)
Transparency key transparency for ESS keys? Transparency.framework; launchd service: com.apple.transparencyd; server: init-kt.apple.com
TTS Text To Speech, command line tool: say; /System/Library/Speech; synthesizer engines: MacinTalk (historic), Polyglot (phoneme-based?), Gryphon (current, DNN-based?)
Transparency un-alterable append-only log to publish information; used for for ESS keys and PCC software hashes, based on CONIKS, devices audit IDS/PCC records against logs, root hashes gossiped over iMessage to detect split-view attacks; Transparency.framework; launchd service: com.apple.transparencyd; server: init-kt.apple.com
TSS Tatsu Signing Server; online verification for firmware signatures; server: gs.apple.com
TTS Text To Speech, neural-network-based synthesis engine (Gryphon); command line tool: say; /System/Library/Speech, /System/Library/TTSPlugins
TVML TV Markup Language; declarative UI language for TV apps; TVMLKit.framework
Ubiquity iCloud Drive; codename Bladerunner, uses CloudKit; CloudDocs.framework; command line tools: fileproviderctl; launchd service: com.apple.bird (iclouddrive-agent); locally stored in ~/Library/Mobile Documents (was supposed to move to Library/CloudStorage/iCloud Drive and iclouddrivectl but this was reverted)
UARP Universal Accessory Restore Protocol; CoreUARP.framework; launchd service: com.apple.uarppersonalizationd (personalized firmware)
Ubiquity iCloud Drive; codename Bladerunner, uses CloudKit; CloudDocs.framework; launchd service: com.apple.bird; locally stored in ~/Library/Mobile Documents (was supposed to move to Library/CloudStorage/iCloud Drive but this was reverted)
UID unique ID key, used as root key for cryptographic subsystems, generated during manufacturing by SEP and fused into hardware, only accessible by SEP
Unified Logging system-wide logging and Activity tracking; launchd service: com.apple.logd, com.apple.diagnosticd; command line tool: log; /dev/oslog; data stored in /var/db/diagnostics, support files in /var/db/uuidtext
User Activity abstraction behind deep-linking into apps with structured context data (people, places); used for Universal Links (with schema.org on websites), Handoff, Parsec, Siri Shortcuts, Proactive; UserActivity.framework; launchd service: com.apple.coreservices.useractivityd
Urchin Tides app on watchOS; /Applications/Urchin.app
USD Universal Scene Description; storage format for 3D assets; /usr/lib/usd; command line tools: usdcat, usdchecker, usdcrush, usdextract, usdrecord, usdtree, usdzip
User Activity abstraction for deep-linking into apps with structured context (people, places); used for Universal Links (schema.org on websites), Handoff, Parsec (app links in search), Quick Note (context awareness); now part of Intents; UserActivity.framework; launchd service: com.apple.coreservices.useractivityd
User Notifications user interface for notification center; launchd service: com.apple.usernoted
UTI Uniform Type Identifiers; system for document types; file extensions and MIME types are mapped to UTIs, UTIs form a conformance graph, apps register their UTIs with Launch Services; /System/Library/CoreServices/CoreTypes.bundle; also Apples hardware devices are represented as UTIs
VA Video Acceleration; AppleGVA.framework, AppleVA.framework, AppleVPA.framework
VDAF Verifiable Distributed Aggregation Function; part of Differential Privacy; VDAF.framework
Viceroy video conferencing used by FaceTime and ReplayKit; ViceroyTrace.framework
Virtualisation running virtual machines on macOS; Hypervisor.framework (for basic VMs and vCPUs), Virtualization.framework (brings a robust set of device models)
VSDB volume status database; /var/db/volinfo.database; command line tool: vsdbutil
Waldo selects edge servers based on approximate location, part of Private Relay, seen in NSP
WFS WebDAV File Sharing; built-in file sharing with Apache; /etc/wfs; command line tool: wfsctl
Widgets content excerpt from apps; provided via a timeline of view hierarchies, configuration uses Intents, technically very similar to complications on watch face; extension point: com.apple.widgetkit-extension
Widgets content excerpt from apps; provided via a timeline of view hierarchies, configuration uses Intents; visible on home screen, lock screen, as live activities, as watch complications; WidgetKit.framework, ChronoServices.framework; extension point: com.apple.widgetkit-extension; launchd service: com.apple.chronod (timeline management and sync)
Willow HomeKit; end-to-end-encrypted communication protocol and API for IoT-accessories; pairing with SRP using code printed on device, credential sync by CKKS, transported over Alloy, remote access using Apple TV as proxy; launchd service: com.apple.homed
Workflow Shortcuts; user-programmable system-wide automation, built-in triggers and actions, extensible with User Activities and Intents; WorkflowKit.framework, ActionKit.framework; locally stored in ~/Library/Shortcuts; launchd service: com.apple.siriactionsd (voice-triggered shortcuts); command line tool: shortcuts
Window Manager implements Stage Manager; /System/Library/CoreServices/WindowManager.app; launchd service: com.apple.WindowManager.agent
Workflow Shortcuts; user-programmable system-wide automation, built-in triggers cause a chain of actions to run; actions are synthesized from User Activities and Intents provided by apps; WorkflowKit.framework, ActionKit.framework; locally stored in ~/Library/Shortcuts; launchd service: com.apple.siriactionsd (voice-triggered shortcuts); command line tool: shortcuts
xART eXtended Anti-Replay Technology; persistent storage for SEP, used by Mesa; /System/Volumes/xarts; launchd service: com.apple.xartstorageremoted; command line tool: xartutil
XCS Xcode Server; continuous integration server; command line tools: xcscontrol, xcsdiagnose
XCS Xcode Server; continuous integration server; command line tools: xcscontrol, xcsdiagnose
XProtect signature-based malware scanner and remediation service; /Library/Apple/System/Library/CoreServices/XProtect.bundle; command line tool: xprotect
1 1TR Term One True Recovery; booting into macOS recovery on Apple Silicon by holding the power button to verify physical presence; enables interaction with SEP to change Boot Policy Description
1 Term Description
2 1TR 1TR One True Recovery; booting into macOS recovery on Apple Silicon by holding the power button to verify physical presence; enables interaction with SEP to change Boot Policy One True Recovery; booting into macOS recovery on Apple Silicon by holding the power button to verify physical presence; enables interaction with SEP to change Boot Policy
3 AA AA Apple account Apple Account
4 AA Apple Archive, see also Apple Encrypted Archive; command line tools: aa, aea, compression_tool
5 AAC AAC Automatic Assessment Configuration; AutomaticAssessmentConfiguration.framework; puts device in a locked mode for exam-style test applications Automatic Assessment Configuration; AutomaticAssessmentConfiguration.framework; puts device in a locked mode for exam-style test applications
6 AAT AAT Apple Advanced Typography; font format and rendering engine Apple Advanced Typography; font format and rendering engine
7 Accounts Accounts launchd service: com.apple.accountsd; /System/Library/Accounts launchd service: com.apple.accountsd; /System/Library/Accounts
8 ACDE ACDC Apple Connect Device External? ACDEClient.framework, old two-step verification, derived from a company-internal AppleConnect system? server: appleconnect.apple.com Apple Chips in Data Centers; see PCC
9 ACDE Apple Connect Device External? ACDEClient.framework, old two-step verification, derived from a company-internal AppleConnect system?
10 ACFS ACFS Apple Clustered File System; deprecated file system for Xsan; acfs.framework Apple Clustered File System; deprecated file system for Xsan; acfs.framework
11 Acoustic ID Acoustic ID Siri feature to recognize songs song recognition and matching with Apple catalog, playback on HomePod; /System/Library/Components/AudioDSP.component
12 Activation Activation cryptographic check-in with iCloud to lock devices reported by the user as lost; verified by iBoot; MobileActivationMacOS.framework; launchd service: com.apple.mobileactivationd; servers: humb.apple.com, albert.apple.com cryptographic check-in with iCloud to lock devices reported by the user as lost; verified by iBoot; MobileActivationMacOS.framework; launchd service: com.apple.mobileactivationd; servers: humb.apple.com, albert.apple.com
13 Activity Activity jobs, coarse-grained work units of applications; tracked by the system across XPC, bears a QoS class for scheduling; low-level mechanism not to be confused with User Activity jobs, coarse-grained work units of applications; tracked by the system across XPC, bears a QoS class for scheduling; low-level mechanism not to be confused with User Activity
14 AE AE Apple Events; messaging system to invoke application functionality; CoreServices.framework/AE.framework; launchd services: com.apple.coreservices.appleevents, com.apple.AEServer (AE over network) Apple Events; messaging system to invoke application functionality; CoreServices.framework/AE.framework; launchd services: com.apple.coreservices.appleevents, com.apple.AEServer (AE over network)
15 AEA Aegir Apple Encrypted Archive; command line tool: aea astronomy watch face and lock screen; /System/Library/CoreServices/AegirProxyApp.app
16 AFM Apple Foundation Model; pre-trained transformer and diffusion models for Greymatter, optimized for on-device use by quantization (with accuracy-recovery adapters) and palletization; command line tool: modelcatalogdump
17 AGC AGC Apple Graphics Control, management of multiple displays and display port connections; launchd service: com.apple.displaypolicyd Apple Graphics Control, management of multiple displays and display port connections; launchd service: com.apple.displaypolicyd
18 AHAP Apple Haptic Audio Pattern; file format for simultaneous audio and haptic data; CoreHaptics.framework
19 AIR AIR Apple Intermediate Representation; synthetic bytecode architecture target for GPU binary toolchain Apple Intermediate Representation; synthetic bytecode architecture target for GPU binary toolchain
20 ALF ALF Application-Level Firewall, launchd service: com.apple.alf (socketfilterfw) Application-Layer Firewall; implemented as a Network Extension (see System Extension); launchd service: com.apple.alf (socketfilterfw); command line tool: socketfilterfw
21 Alloy Alloy substrate for communication between user devices over Bluetooth and devices to iCloud, implemented over IDS; /System/Library/IdentityServices/ServiceDefinitions; launchd service: com.apple.identityservicesd substrate for communication between user devices over Bluetooth and devices to iCloud, implemented over IDS; /System/Library/IdentityServices/ServiceDefinitions; launchd service: com.apple.identityservicesd
22 ALS ALS Ambient Light Sensor, AmbientDisplay.framework Ambient Light Sensor, AmbientDisplay.framework
23 Amber Amber Swift UI; SwiftUI.framework Swift UI; SwiftUI.framework
24 AMFI AMFI Apple Mobile File Integrity, checks code integrity based on code signature, stronger enforcement with hardened runtime, validates entitlement restrictions; launchd service: com.apple.MobileFileIntegrity (amfid, invoked by kernel through host special port 18); disabled by setting amfi_get_out_of_my_way=0x1 in boot-args Apple Mobile File Integrity, checks code integrity based on code signature, stronger enforcement with hardened runtime, validates entitlement restrictions and environment constraints (launch constraints, library constraints); launchd service: com.apple.MobileFileIntegrity (amfid, invoked by kernel through host special port 18); disabled by setting amfi_get_out_of_my_way=0x1 in boot-args
25 AMP AMP Apple Media Protocol? former parts of iTunes for iPod and iOS device access in Finder, Home Sharing; AMPDevices.framework, AMPSharing.framework; launchd services: com.apple.AMPDeviceDiscoveryAgent, com.apple.AMPDevicesAgent, com.apple.amp.mediasharingd Apple Media Protocol? former parts of iTunes for iPod and iOS device access in Finder, Home Sharing; AMPDevices.framework, AMPSharing.framework; launchd services: com.apple.AMPDeviceDiscoveryAgent, com.apple.AMPDevicesAgent, com.apple.amp.mediasharingd
26 AMP AMP Asynchronous Multiprocessing; performance and power-efficiency cores on Apple Silicon Asynchronous Multiprocessing; performance and power-efficiency cores on Apple Silicon
27 AMS AMS Apple Media Services; formerly the iTunes stores and media services: App Stores, Apple Music, Apple TV, iCloud media library, Apple Podcasts, Podcast sync, Books Store, Books sync; AppleMediaServices.framework; server: phobos.apple.com Apple Media Services; formerly the iTunes stores and media services: App Stores, Apple Music, Apple TV, iCloud media library, Apple Podcasts, Podcast sync, Books Store, Books sync; AppleMediaServices.framework; server: phobos.apple.com
28 AMX AMX Apple Matrix Extension; ARM instruction set extension for matrix operations Apple Matrix Extension; ARM instruction set extension for matrix operations
29 ANE Apple Neural Engine, hardware accelerator for neural network operations; ANECompiler.framework, ANEServices.framework; launchd service: com.apple.aned
30 Anisette Anisette two-factor authentication creates security codes on trusted devices using TOTP, probably using Circle keys, checked by HSA; AuthKit.framework; launchd service: com.apple.akd two-factor authentication creates security codes on trusted devices using TOTP, probably using Circle keys, checked by HSA; AuthKit.framework; launchd service: com.apple.akd
31 AOP AOP Always On Processor, part of Apple SoCs, runs RTKit as operating system Always On Processor, part of Apple SoCs, runs RTKit as operating system
32 AOS AOS Apple Online Services? historical name for iCloud Apple Online Services? historical name for iCloud
33 Apache Apache built-in web server; command line tool: apachectl built-in web server; command line tool: apachectl
34 APFS APFS Apple File System; copy-on-write file system with support for volume space-sharing, per-file encryption, and snapshots Apple File System; copy-on-write file system with support for volume space-sharing, per-file encryption, and snapshots
35 APNS APNS Apple Push Notification service, server infrastructure for remote push notifications over a single connection, clients subscribe to push topics, can be authenticated by app (remote notifications), device (Find My …), or Apple ID login (DSID); credentials in apsd keychain; launchd service: com.apple.apsd; server: push.apple.com Apple Push Notification service, server infrastructure for remote push notifications over a single connection, clients subscribe to push topics, can be authenticated by app (remote notifications), device (Find My …), or Apple Account login (DSID); credentials in apsd keychain; launchd service: com.apple.apsd; server: push.apple.com
36 App Nap App Nap quiescence detection for applications and corresponding self-demotion in scheduler parameters, implemented within application frameworks and RunningBoard, listens for occlusion notifications from WindowServer quiescence detection for applications and corresponding self-demotion in scheduler parameters, implemented within application frameworks and RunningBoard, listens for occlusion notifications from WindowServer
37 App Sandbox App Sandbox Seatbelt-based sandbox for apps; /System/Library/Sandbox/Profiles/application.sb; enabled with com.apple.security.app-sandbox entitlement; launchd service: com.apple.secinitd Seatbelt-based sandbox for apps; /System/Library/Sandbox/Profiles/application.sb; enabled with com.apple.security.app-sandbox entitlement; launchd service: com.apple.secinitd
38 AppleCare AppleCare extended warranty; NewDeviceOutreach.framework; launchd service: com.apple.ndoagent extended warranty; NewDeviceOutreach.framework; launchd service: com.apple.ndoagent
39 APT APT Adaptive Picture Timing? ProMotion; dynamic screen updates with 120Hz base frequency; AppleDisplayTCONControl.framework Adaptive Picture Timing? ProMotion; dynamic screen updates with 120Hz base frequency; AppleDisplayTCONControl.framework
40 Ask To parental-controlled user can ask parent for exceptions; launchd service: com.apple.asktod; AskToCore.framework
41 ASL ASL Apple System Logger, superseded by Unified Logging; /etc/asl; stored in /var/log/asl; launchd service: com.apple.syslogd; command line tool: syslog Apple System Logger, superseded by Unified Logging; /etc/asl; stored in /var/log/asl; launchd service: com.apple.syslogd; command line tool: syslog
42 ASR ASR Apple Software Restore; restore entire volumes from sources like disk images (HDI, SIU), also restores based on APFS snapshots and snapshot deltas; command line tool: asr Apple Software Restore; restore entire volumes from sources like disk images (HDI, SIU), also restores based on APFS snapshots and snapshot deltas; command line tool: asr
43 Assertions Assertions power state management allowing applications to prevent sleeping; launchd service: com.apple.powerd; command line tools: caffeinate, pmset power state management allowing applications to prevent sleeping; launchd service: com.apple.powerd; command line tools: caffeinate, pmset
44 Assessment Assessment checking of System Policy; term also used for AAC checking of System Policy; term also used for AAC
45 Asset Cache Asset Cache discretionary caching server for Mobile Assets, Packages, iOS updates, App Store content, ODR, MMCS data; launchd services: com.apple.AssetCache.builtin, com.apple.AssetCacheLocatorService, com.apple.AssetCacheManagerService, com.apple.AssetCacheTetheratorService; command line tools: AssetCacheLocatorUtil, AssetCacheManagerUtil, AssetCacheTetheratorUtil discretionary caching server for Mobile Assets, Packages, iOS updates, App Store content, ODR, MMCS data; launchd services: com.apple.AssetCache.builtin, com.apple.AssetCacheLocatorService, com.apple.AssetCacheManagerService, com.apple.AssetCacheTetheratorService; command line tools: AssetCacheLocatorUtil, AssetCacheManagerUtil, AssetCacheTetheratorUtil
46 Assistant Assistant Siri; dictation and semantic understanding, Intent is communicated to and enacted on the client, uses TTS; /System/Library/Assistant, AssistantServices.framework; server: *.siri.apple.com Siri; speech recognition and semantic understanding, dialog management by CDM, Intent is communicated to and enacted on the client, uses TTS for speech output, Snippets to embed mini UIs into responses; /System/Library/Assistant, /System/Library/Snippets, AssistantServices.framework; server: *.siri.apple.com
47 ATS ATS App Transport Security, sandbox mechanism only allowing TLS-secured connections App Transport Security, sandbox mechanism only allowing TLS-secured connections
48 ATSUI ATSUI Apple Type Services for Unicode Imaging; rendering engine superseded by CoreText.framework, font management; ApplicationServices.framework/ATS.framework; launchd service: com.apple.xtyped (fontd); command line tools: atsutil Apple Type Services for Unicode Imaging; rendering engine superseded by CoreText.framework, font management; ApplicationServices.framework/ATS.framework; launchd service: com.apple.xtyped (fontd); command line tools: atsutil
49 ATT ATT App Tracking Transparency; apps declare user tracking on app store App Tracking Transparency; apps declare user tracking on app store
50 Attestation Attestation cryptographic proof of a genuine SEP; used for web authentication and app attestation; DeviceCheck.framework; online service signs a GID-based challenge response? used to pair RemoteXPC channel? stripped down variant used to securely identify Touch ID keyboards cryptographic proof of a genuine SEP; used for web authentication and app attestation; DeviceCheck.framework; SEP responds to challenge using hardware-key (GID, PKA), online service verifies; used to pair Touch ID keyboards, used to pair RemoteXPC channel?
51 Authorization Authorization discretionary access control policies for high-level services; similar to PAM; policy stored in /var/db/auth.db discretionary access control policies for high-level services; similar to PAM; policy stored in /var/db/auth.db
52 Avatar Avatar Memoji and Animoji (face tracking); AvatarKit.framework Memoji and Animoji, including pre-rendered iMessage stickers; AvatarKit.framework
53 AVB AVB Audio Video Bridging, low-latency audio over Ethernet; launchd service: com.apple.avbdeviced; command line tool: avbdiagnose, avbutil Audio Video Bridging, low-latency audio over Ethernet; launchd service: com.apple.avbdeviced; command line tools: avbanalyse, avbdiagnose, avbutil
54 AWD AWD Apple Wireless Diagnostics, sends system telemetry to Apple; CoreAnalytics.framework, WirelessDiagnostics.framework; launchd services: com.apple.awdd, com.apple.analyticsd Apple Wireless Diagnostics, sends system telemetry to Apple; CoreAnalytics.framework, WirelessDiagnostics.framework; launchd services: com.apple.awdd, com.apple.analyticsd
55 AWDL AWDL Apple Wireless Direct Link; secondary WiFi interface that runs in parallel to an active WiFi access point connection, similar to WiFi Direct (p2p interface), uses a randomized MAC, used for peer-to-peer networking: AirDrop, AirPlay; DeviceToDeviceManager.framework Apple Wireless Direct Link; secondary WiFi interface that runs in parallel to an active WiFi access point connection, similar to WiFi Direct (p2p interface), uses a randomized MAC, used for peer-to-peer networking: AirDrop, AirPlay; DeviceToDeviceManager.framework
56 Background Assets assets that an app extension loads without the app being launched; BackgroundAssets.framework; extension point: com.apple.background-asset-downloader-extension; launchd service: com.apple.backgroundassets.user
57 Bezel Bezel on-screen overlays for hardware volume buttons, screen brightness, Bluetooth HID, and others; /Library/Application Support/Apple/BezelServices, launchd services: com.apple.loginwindow, com.apple.OSDUIHelper on-screen overlays for hardware volume buttons, screen brightness, Bluetooth HID, and others; /Library/Application Support/Apple/BezelServices, launchd services: com.apple.loginwindow, com.apple.OSDUIHelper
58 Biome Bifrost CloudKit-based datastream and sync engine; BiomeStreams.framework, BiomeSync.framework; launchd services: com.apple.BiomeAgent, com.apple.biomesyncd emergency satellite connectivity; /System/Library/LocationBundles/Bifrost.bundle
59 Blast Door Biome sandboxed sanitization process for untrusted iMessage input; BlastDoor.framework CloudKit-synced streaming and storage of events like donated and invoked Intents; semantic index to ground AI with personal context; BiomeStreams.framework, BiomeSync.framework; launchd services: com.apple.BiomeAgent, com.apple.biomesyncd; embedding vector extraction and storage: ZeoliteFramework.framework
60 Blast Door sandboxed sanitization process for untrusted input, used for iMessage, IDS, Telephony, media analysis; BlastDoor.framework, CTBlastDoorSupport.framework, IDSBlastDoorSupport.framework, MediaAnalysisBlastDoorSupport.framework, MessagesBlastDoorSupport.framework, TelephonyBlastDoorSupport.framework
61 BOM BOM Bill of Materials; format to store contents of installer Packages; command line tool: lsbom Bill of Materials; format to store contents of installer Packages; command line tool: lsbom
62 Bonjour Bonjour mDNS; launchd service: com.apple.mDNSResponder.reloaded; command line tool: dns-sd mDNS; launchd service: com.apple.mDNSResponder.reloaded; command line tool: dns-sd
63 Boot Cache Boot Cache disk cache pre-heating at boot time with typically loaded applications; /var/db/BootCaches; launchd service: com.apple.warmd disk cache pre-heating at boot time with typically loaded applications; /var/db/BootCaches; launchd service: com.apple.warmd
69 Cache Delete Cache Delete cleanup for various caches; /System/Library/CacheDelete; launchd service: com.apple.cache_delete (deleted) cleanup for various caches; /System/Library/CacheDelete; launchd service: com.apple.cache_delete (deleted)
70 CAML CAML Core Animation Markup Language; XML file format for layers, shapes and animations Core Animation Markup Language; XML file format for layers, shapes and animations
71 Carousel Carousel derivative of SpringBoard for Watch home screen, watch face, and notification center derivative of SpringBoard for Watch home screen, watch face, and notification center
72 Celestial CBOR media streaming used by ReplayKit for game broadcasts; Celestial.framework Concise Binary Object Representation; JSON-inspired compact binary data serialization; CBORLibrary.framework
73 CDHash Code Directory Hash; a hash of hashes over the parts of a code bundle; command line tool: codesign
74 CDM Continuous Dialog Manager; natural dialog with Siri, MARRS for multi-modality; ContinuousDialogManagerService.framework
75 CEC Consumer Electronics Control; remote control for HDMI-connected devices; CoreRC.framework, IOCEC.framework
76 Celestial media streaming used by ReplayKit for in-app screen broadcasts; Celestial.framework; launchd service: com.apple.replayd
77 Certificates Certificates validity checked using CRLs, OCSP stapling, and transparency logs; /System/Library/Security/Certificates.bundle; launchd services: com.apple.trustd, com.apple.trustd.agent, com.apple.ocspd; command line tool: crlrefresh validity checked using CRLs, OCSP stapling, and transparency logs; /System/Library/Security/Certificates.bundle; launchd services: com.apple.trustd, com.apple.trustd.agent, com.apple.ocspd; command line tool: crlrefresh
78 Circle Chamois cryptographic primitive to exchange public keys of all trusted devices of one user, signed by all Circle peers; iCloud identity keypair as an additional Circle peer, triggers countersigning from all trusted devices, private key synced across all trusted devices, new devices can pull this key from Secure Backup to join the Circle; used by CKKS; KeychainCircle.framework; command line tools: tpctl, otctl (Octagon trust is newer?) Stage Manager
79 CKKS CHIP CloudKit Key Sync, end-to-end secure syncing for credentials, seeded by Circle, transferred items stored ephemerally using OTR protocol; currently includes ApplePay, AutoUnlock, CreditCards, DevicePairing, Engram, Health, Home, Manatee, SOS, WiFi and other keys; launchd service: com.apple.secd; command line tool: ckksctl Connected Home over IP; Matter; integrated into HomeKit, can use Thread as transport layer; HomeKitMatter.framework, CoreThread.framework; launchd services: com.apple.threadradiod, com.apple.ThreadCommissionerService
80 Classroom Circle launchd service: com.apple.studentd cryptographic primitive to exchange public keys of trusted devices of a user, signed by Circle peers; iCloud identity added as additional Circle peer, private key synced across all trusted devices, new devices can pull this key from Secure Backup to join the Circle; per-device Circles stored in CKKS for two-factor accounts (Octagon); KeychainCircle.framework; command line tools: otctl (Octagon)
81 CKKS CloudKit Key Sync, end-to-end secure syncing for credentials, seeded by Circle; currently includes ApplePay, AutoUnlock, CreditCards, DevicePairing, Engram, Health, Home, Manatee, SOS, WiFi and other keys; launchd service: com.apple.secd; command line tool: ckksctl
82 Clarity customizable accessibility mode for simplified UI; ClarityFoundation.framework
83 Classroom school teachers can create assignments for student iPads and track progress in Schoolwork app; ClassKit.framework; launchd service: com.apple.studentd
84 Cloud Pairing Cloud Pairing part of Alloy, Bluetooth out-of-band pairing over iCloud for Continuity; launchd service: com.apple.BTServer.cloudpairing (cloudpaird) part of Alloy, Bluetooth out-of-band pairing over iCloud for Continuity; launchd service: com.apple.BTServer.cloudpairing (cloudpaird)
85 CMAS CMAS Commerial Mobile Alert System, now known as Wireless Emergency Alerts (WEA) Commerial Mobile Alert System, now known as Wireless Emergency Alerts (WEA)
86 Commpage Commpage user-mapped kernel data, like vdso/vsyscall on Linux; mapped at 0x7fffffe00000 user-mapped kernel data, like vdso/vsyscall on Linux; mapped at 0x7fffffe00000
87 Communications Filter Communications Filter recipient blocking for iMessage, FaceTime, Mail; launchd service: com.apple.cmfsyncagent recipient blocking for iMessage, FaceTime, Mail; launchd service: com.apple.cmfsyncagent
88 Companion Companion iPhone that is paired with Watch; communication uses Alloy over IPsec over Bluetooth iPhone that is linked with Watch, Mac, or Apple TV; communication with Watch uses Alloy over IPsec over Bluetooth, AWDL on demand; launchd service: com.apple.companiond; Bonjour service: _companion-link._tcp
89 Continuity Contact Key Verification umbrella term for Handoff, Sidecar, SMS relay, Universal Clipboard, Watch unlock, WiFi call relay and others; SMS relay works by proxying to iMessage, other services use Alloy code for manual verification of iMessage keys; code identifies a long-lived account key stored in iCloud Keychain, which signs all ESS device keys
90 Continuity umbrella term for Handoff, Sidecar, iPhone Mirroring, SMS relay, Universal Clipboard, Watch unlock, WiFi call relay and others; SMS relay works by proxying to iMessage, other services use Alloy for signalling and AWDL for payload; /System/Applications/iPhone Mirroring.app, ScreenContinuityServices.framework
91 Control Center Control Center icons in menu/status bar and Bento Box controls UI, gradually replaces SystemUIServer on macOS; handles incoming AirPlay content; launchd services: com.apple.controlcenter, com.apple.SystemUIServer.agent icons in menu/status bar and Bento Box controls UI, gradually replaces SystemUIServer on macOS; handles incoming AirPlay content; launchd services: com.apple.controlcenter, com.apple.SystemUIServer.agent
92 CPML CPML CorePrediction Machine Learning; CPMLBestShim.framework CorePrediction Machine Learning; CPMLBestShim.framework
93 CRD CRD Conference Room Display; Apple TV mode Conference Room Display; Apple TV mode
94 Cryptex Cryptographically sealed Extension of SSV, mount-invisible extension of the root volume, allows lightweight updates as part of Rapid Security Response; /System/Cryptexes (mountpoint), /System/Volumes/Preboot/*/cryptex1/current/*.dmg (disk images)
95 CSR Configurable Security Restrictions; XNU subsystem that is the basis for SIP
96 CTK CTK Crypto Token Kit; smart card management, also for the Secure Element on iOS? launchd service: com.apple.ctkd; command line tool: sc_auth Crypto Token Kit; smart card management, also for the Secure Element on iOS? launchd service: com.apple.ctkd; command line tool: sc_auth
97 CTS CTS Centralized Task Scheduling; execution of DAS tasks; /System/Library/UserEventPlugins/com.apple.cts.plugin Centralized Task Scheduling; execution of DAS tasks; /System/Library/UserEventPlugins/com.apple.cts.plugin
98 CVMS CVMS Core VM Server/Service? compilation of GPU shaders; launchd service: com.apple.cvmsServ Core VM Server/Service? compilation of GPU shaders; launchd service: com.apple.cvmsServ
99 DAAP DAAP Digital Audio Access Protocol; used by Home Sharing (with Rapport token) and by the Remote app to control Apple TV (with pairing token); payload unencrypted; DAAPKit.framework; Bonjour services: _atc._tcp, _home-sharing._tcp, _mediaremotetv._tcp, _touch-able._tcp Digital Audio Access Protocol; used by Home Sharing (with Rapport token) and by the Remote app to control Apple TV (with pairing token); payload unencrypted; DAAPKit.framework; Bonjour services: _atc._tcp, _home-sharing._tcp, _mediaremotetv._tcp, _touch-able._tcp
100 Daily Briefing Daily Briefing Siri giving an overview of information for the day; SiriDailyBriefingInternal.framework Siri giving an overview of information for the day; SiriDailyBriefingInternal.framework
101 DART DART DMA Address Relocation Table; IOMMU implementation in Apple silicon, positioned in front of peripheral devices, offers sub-page protection; SART: streaming variant for high-throughput devices (like NVMe) DMA Address Relocation Table; IOMMU implementation in Apple silicon, positioned in front of every DMA-capable co-processor and peripheral, offers sub-page protection; SART: streaming variant for high-throughput devices (like NVMe)
102 Darwin Directory static store for users and groups, saves Open Directory interaction for the local case? /usr/lib/system/libsystem_darwindirectory.dylib, /System/Library/DarwinDirectory, /private/var/db/DarwinDirectory; command line tool: dddiagnose
103 DAS DAS Duet Activity Scheduler; scheduling policy engine behind NSBackgroundActivityScheduler and XPC activities; /System/Library/DuetActivityScheduler; launchd service: com.apple.dasd Duet Activity Scheduler; scheduling policy engine behind NSBackgroundActivityScheduler and XPC activities; /System/Library/DuetActivityScheduler; launchd service: com.apple.dasd
104 Data Detectors Data Detectors text analysis to highlight phone numbers, street addresses, and the like; DataDetectors.framework text analysis to highlight phone numbers, street addresses, and the like; DataDetectors.framework
105 Data Vault Data Vault directories with the UF_DATAVAULT special flag; CSR limits access to one application directories with the UF_DATAVAULT special flag; CSR limits access to one application
106 DAV DAV Distributed Authoring and Versioning; network protocol on top of HTTP for syncing calendars (CalDAV), contacts (CardDAV), and formerly also bookmarks (BookmarkDAV) Distributed Authoring and Versioning; network protocol on top of HTTP for syncing calendars (CalDAV), contacts (CardDAV), and formerly also bookmarks (BookmarkDAV)
107 DCP Display Co-Processor
108 DDE Device Discovery Extension; detects devices on local network without app access to local network; DeviceDiscoveryExtension.framework, DeviceDiscoveryUICore.framework; extension point: com.apple.discovery-extension
109 DEP DEP Device Enrollment Program; devices check in with Apple during Setup Assistant to query for their enrollment status, retrieve MDM server URL to fetch initial configuration profile Device Enrollment Program; devices check in with Apple during Setup Assistant to query for their enrollment status, retrieve MDM server URL to fetch initial configuration profile
110 Developer Mode enables launching of self-compiled apps in iOS, rough equivalent to System Policy; command line tool: devmodectl
111 DFR DFR Dynamic Function Row?, TouchBar; /System/Library/CoreServices/ControlStrip.app; DFRFoundation.framework Dynamic Function Row?, TouchBar; /System/Library/CoreServices/ControlStrip.app; DFRFoundation.framework
112 DFU DFU Device Firmware Update; special boot mode where iOS has not booted and the system can be installed over the Lightning connection Device Firmware Update; special boot mode where iOS has not booted and the system can be installed over the Lightning connection
113 Differential Privacy Differential Privacy crowdsourcing without user tracking; privacy budget for management of anonymity set; used for keyboard words, emoji, Spotlight searches, Parsec deep links, HealthKit usage, Safari telemetry; /System/Library/DifferentialPrivacy; stored in /var/db/DifferentialPrivacy; launchd service: com.apple.dprivacyd crowdsourcing without user tracking; privacy budget for management of anonymity set; used for keyboard words, emoji, Spotlight searches, Parsec deep links, HealthKit usage, Safari telemetry; /System/Library/DifferentialPrivacy; stored in /var/db/DifferentialPrivacy; launchd service: com.apple.dprivacyd
114 Digital Separation safety check feature to inhibit sharing relationships; DigitalSeparation.framework
115 DMC Device Management Client; part of MDM; DMCUtilities.framework
116 DMC Disk Mount Conditioner; simulates slow IO devices; command line tool: dmc
117 DND DND Do Not Disturb Do Not Disturb
118 Domain Association Dose signed files in .well-known directory on websites; equivalent to Entitlements for websites ambient sound level checking on Watch; /Applications/Dose.app
119 DSID DSID Destination Signaling Identifier, unique ID for IDS login on a specific device Destination Signaling Identifier, unique ID for IDS login on a specific device
120 DTrace DTrace system-wide tracing infrastructure, command line tools: dtrace, *.d, dappprof, dapptrace, dtruss, errinfo, execsnoop, fddist, fs_usage, imptrace, iopattern, iopending, iosnoop, iotop, lastwords, latency, opensnoop, plockstat, rwsnoop, sampleproc, sc_usage, topsyscall, topsysproc system-wide tracing infrastructure, command line tools: dtrace, *.d, dappprof, dapptrace, dtruss, errinfo, execsnoop, fddist, fs_usage, imptrace, iopattern, iopending, iosnoop, iotop, lastwords, latency, opensnoop, plockstat, rwsnoop, sampleproc, sc_usage, topsyscall, topsysproc
121 Duet Duet telemetry collection engine for system and user events, forecasting by machine learning, backend for DAS, Proactive, Relevance, Screen Time, thermal and battery management; /System/Library/DuetKnowledgeBase; CoreDuet.framework, CoreKnowledge.framework, CorePrediction.framework; launchd services: com.apple.coreduetd, com.apple.knowledge-agent telemetry collection engine for system and user events, forecasting by machine learning, backend for DAS, Proactive, Relevance, Screen Time, thermal and battery management; /System/Library/DuetKnowledgeBase, /System/Library/DuetExpertCenter; CoreDuet.framework, CoreKnowledge.framework, CorePrediction.framework, CascadeEngine.framework (link to Biome); launchd services: com.apple.coreduetd, com.apple.duetexpertd, com.apple.knowledge-agent, com.apple.ospredictiond
122 Dyld Shared Cache Dyld Shared Cache dynamic linker cache, stores all system libraries in prelinked form, original library files are removed; /System/Library/dyld; command line tool: update_dyld_shared_cache dynamic linker cache, stores all system libraries in prelinked form, original library files are removed; /System/Volumes/Preboot/Cryptexes/OS/System/Library/dyld; command line tools: dyld_info, dyld_usage, update_dyld_shared_cache
123 EAS EAS Exchange Active Sync; network protocol for accessing Microsoft Exchange servers Exchange Active Sync; network protocol for accessing Microsoft Exchange servers
124 EDR EDR Extended Dynamic Range; rendering with transfer function extending beyond sRGB white; implemented natively on XDR displays and by backlight modulation on others; HDRProcessing.framework Extended Dynamic Range; rendering with transfer function extending beyond sRGB white; implemented natively on XDR displays and by backlight modulation on others; HDRProcessing.framework
125 Energy Impact Energy Impact unitless metric for per-application energy consumption, machine-specific coefficients; /usr/share/pmenergy, /usr/share/kpep; launchd services: com.apple.sysmond, com.apple.thermald; command line tool: powermetrics unitless metric for per-application energy consumption, machine-specific coefficients; /usr/share/pmenergy, launchd services: com.apple.sysmond, com.apple.thermald; command line tool: powermetrics
126 Engram Engram Messages in iCloud; devices store received iMessages in CloudKit; Engram.framework Messages in iCloud; devices store received iMessages in CloudKit; Engram.framework
127 Entitlements Entitlements capability-like attributes bound to executables by code signing; some entitlements like App Sandbox restrict ambient authority, some gradually relieve those restrictions (using Seatbelt), some services or system calls grant privilege based on caller entitlements capability-like attributes bound to executables by code signing; some entitlements like App Sandbox restrict ambient authority, some gradually relieve those restrictions (using Seatbelt), some services or system calls grant privilege based on caller entitlements
128 ESS ESS IDS user directory, public key distribution for iMessage and CloudKit sharing, uses Transparency; server: *.ess.apple.com; launchd service: com.apple.identityservicesd IDS user directory, public key distribution for iMessage and CloudKit sharing, uses Transparency; server: *.ess.apple.com; launchd service: com.apple.identityservicesd
129 Event Monitor Exclave simple rules engine for running commands on various systen events; apparently not used by default; /etc/emond.d, /var/db/emondClients; launchd service: com.apple.emond user-level portions of kernel or SEP services, used for paravirtualized access by VMs; /usr/libexec/init_exclavekit
130 Eye Relief screen distance warning for handheld devices; /Applications/EyeReliefUI.app
131 FaceTime FaceTime video calls, employs the ICE (establishing peer-to-peer connection), STUN (session credential exchange) and SRTP (encrypted media streaming) protocols; FTServices.framework; launchd services: com.apple.videoconference.camera (avconferenced) video calls, employs the ICE (establishing peer-to-peer connection), STUN (session credential exchange) and SRTP (encrypted media streaming) protocols; FTServices.framework; launchd services: com.apple.videoconference.camera (avconferenced)
132 FairPlay FairPlay DRM system used by app and media stores; CoreADI.framework, CoreFP.framework, CoreLSKD.framework; launchd services: com.apple.adid, com.apple.fairplayd (invoked by kernel through host special port 17), com.apple.lskdd; credentials stored in /var/db/fpsd DRM system used by app and media stores; CoreADI.framework, CoreFP.framework, CoreLSKD.framework; launchd services: com.apple.adid, com.apple.fairplayd (invoked by kernel through host special port 17), com.apple.lskdd; credentials stored in /var/db/fpsd
133 Family Circle Family Circle Family Sharing; launchd services: com.apple.familycircled, com.apple.askpermissiond Family Sharing; launchd services: com.apple.familycircled, com.apple.askpermissiond
134 FDE FDE Full Disk Encryption, FileVault; command line tool: fdesetup, sysadminctl Full Disk Encryption, FileVault; command line tool: fdesetup, sysadminctl
135 FDR FDR Factory Data/Device Reset? ensures that no downgrades are performed? servers: skl.apple.com, gg.apple.com; /System/Library/FDR Factory Data/Device Reset? ensures that no downgrades are performed? servers: skl.apple.com, gg.apple.com; /System/Library/FDR
136 Feldspar Feldspar Apple News; Silex.framework Apple News; Silex.framework
137 FiDES FiDES Fi? Distributed Evaluation Service? aggregates Differential Privacy data for unlinkability? maybe private federated learning? used for emoji, Suggestions, Dictation; /System/Library/DistributedEvaluation; DistributedEvaluation.framework; server: fides-pol.apple.com Fi? Distributed Evaluation Service? aggregates Differential Privacy data for unlinkability? used for emoji, Suggestions, Dictation; /System/Library/DistributedEvaluation; DistributedEvaluation.framework, FedStats.framework (private federated learning?); server: fides-pol.apple.com
138 Find My … File Provider location sharing by explicitly querying devices remotely or collateral beacon detection using Search Party; FMCore.framework, FMF.framework; launchd service: com.apple.icloud.fmfd (find my friends) infrastructure and extension system for syncing with cloud providers; placeholder files based on SF_DATALESS attribute in APFS; FileProvider.framework; locally stored in ~/Library/CloudStorage; command line tool: fileproviderctl
139 Find My location sharing by explicitly querying devices remotely or collateral beacon detection using Search Party; FMCore.framework, FMF.framework; launchd service: com.apple.icloud.fmfd (find my friends)
140 Firmlink Firmlink bi-directional non-symbolic link between the read-only system volume and the data volume, additional symlinks and mountpoints in the root directory are virtually allocated; /usr/share/firmlinks, /etc/synthetic.conf bi-directional non-symbolic link between the read-only system volume and the data volume, additional symlinks and mountpoints in the root directory are virtually allocated; /usr/share/firmlinks, /etc/synthetic.conf
141 Focus Focus restriction modes for notification presentation; Focus.framework, DoNotDisturb.framework; local settings in ~/Library/DoNotDisturb restriction modes for notification presentation; focus filters for in-app display restrictions, communicated by Intents; Focus.framework, DoNotDisturb.framework; local settings in ~/Library/DoNotDisturb
142 FollowUp FollowUp user interaction for Secure Backup wrapping with device passcode, CoreFollowUp.framework; launchd service: com.apple.followupd user interaction for Secure Backup wrapping with device passcode, CoreFollowUp.framework; launchd service: com.apple.followupd
143 FoundationDB FoundationDB fundamental iCloud storage database, marketed as CloudKit, separated into containers; records, blobs, and large asset storage with MMCS, server-side continuous queries can trigger push notifications, user management by IDS, sharing between users; PCS keys used for hierarchical zone, record, and asset encryption; CloudKitDaemon.framework; launchd service: com.apple.cloudd; locally stored in ~/Library/Caches/CloudKit, ~/Library/Containers/*/Data/CloudKit; command line tool: cktool fundamental iCloud storage database, marketed as CloudKit, separated into containers; records, blobs, and large asset storage with MMCS, server-side continuous queries can trigger push notifications, user management by IDS, sharing between users by GroupKit; PCS keys used for hierarchical zone, record, and asset encryption; CloudKitDaemon.framework; launchd service: com.apple.cloudd; locally stored in ~/Library/Caches/CloudKit, ~/Library/Containers/*/Data/CloudKit; command line tool: cktool
144 FPR FPR Fast Permission Restrictions; Apple CPU registers to downgrade (old APRRs do bitmasking) or remap (SPRRs since M1) actual permissions of memory pages per thread; used for JIT protection and by AMFI to freeze user code after checking Fast Permission Restrictions; Apple CPU registers to downgrade (old APRRs do bitmasking) or remap (SPRRs since M1) actual permissions of memory pages (the CTRR region) per thread; used for JIT protection and by AMFI to freeze user code after checking
145 FUD FSKit Firmware Update Daemon; /var/db/fud; launchd service: com.apple.MobileAccessoryUpdater user space file system support; kernel stub file system is /System/Library/Extensions/lifs.kext; file systems are in /System/Library/ExtensionKit/Extensions/com.apple.fskit.*; launchd service: com.apple.filesystems.fskitd, com.apple.filesystems.doubleagentd (handling of Apple double files in user space); extension point: com.apple.fskit.fsmodule
146 FUD Firmware Update Daemon; see TSS, UARP; launchd service: com.apple.accessoryupdaterd
147 Game Mode auto-activates when games are shown full screen, throttles background work, lowers audio and input latency; launchd service: com.apple.gamepolicyd
148 GID GID group ID key, shared across all devices of the same SoC generation, derived keys are used to prove device type over the network, only accessible by SEP group ID key, shared across all devices of the same SoC generation, derived keys are used to prove device type over the network, only accessible by SEP
149 Gizmo Gizmo Apple Watch; watch settings managed by Companion; /Applications/Bridge.app, /System/Library/BridgeManifests Apple Watch; watch settings managed by Companion iPhone; /Applications/Bridge.app, /System/Library/BridgeManifests
150 Greymatter Apple Intelligence; on-device language and diffusion models, larger server-based models in PCC; AFM refined for specific tasks (queries, summarization, categorization) by adapters (parameter for inserted network modules); grounded with context from Biome and intelligence stores; ~/Library/IntelligencePlatform; launchd service: com.apple.modelmanagerd (model residency management); /System/Library/ModelManager/Policy.plist; /Applications/Tamale.app (Camera Control integration); command line tool: csfdiagnose (cloud subscription features), modelmanagerdump
151 Group Activities Group Activities SharePlay; sharing of media content and programmatic state over FaceTime calls; GroupActivities.framework, CopresenceCore.framework; launchd service: com.apple.telephonyutilities.callservicesd SharePlay; sharing of media content and programmatic state over FaceTime calls; GroupActivities.framework, CopresenceCore.framework; launchd service: com.apple.telephonyutilities.callservicesd
152 GroupKit groups of IDS users with shared CloudKit (PCS) access; GroupKit.framework
153 GSS GSS Generic Security Service; part of Kerberos; GSS.framework; launchd service: com.apple.gssd (invoked by kernel through host special port 19); command line tool: gsstool Generic Security Service; part of Kerberos; GSS.framework; launchd service: com.apple.gssd (invoked by kernel through host special port 19); command line tool: gsstool
154 GXF GXF Guarded Execution Feature/Fault, additional exception levels on Apple Silicon, lateral to the usual exception levels; page tables remain the same, but interpretation of permission bits changes by way of FPR, genter and gexit instructions; implements lightweight intra-address-space protection contexts Guarded Execution Feature/Fault, additional exception levels on Apple Silicon, lateral to the usual exception levels; page tables remain the same, but interpretation of permission bits changes by way of FPR, genter and gexit instructions; implements lightweight intra-address-space protection contexts
155 HAP HAP Home Automation Protocol; CoreHAP.framework Home Automation Protocol; CoreHAP.framework
156 HDA HDA High Definition Audio; HDAInterface.framework High Definition Audio; HDAInterface.framework
157 HDI HDI Hard Disk Image; command line tool: hdiutil Hard Disk Image; command line tool: hdiutil
158 HeadBoard HeadBoard derivative of SpringBoard for tvOS home screen; /Applications/HeadBoard.app, /Applications/PineBoard.app derivative of SpringBoard for tvOS home screen; /Applications/HeadBoard.app, /Applications/PineBoard.app
159 Health Balance vitals app on Watch; /Applications/NanoHealthBalance.app
160 HLS HLS HTTP Live Streaming HTTP Live Streaming
161 HomeEnergy HomeKit management for grid energy supply; EnergyKit.framework
162 HSA HSA Hardware Security Architecture; version 1 used for two-step verification, SOS with iCSC; version 2 for two-factor authentication, CKKS and Secure Backup with iCDP Hardware Security Architecture; version 1 used for two-step verification, SOS with iCSC; version 2 for two-factor authentication, CKKS and Secure Backup with iCDP
163 HSM HSM Hardware Security Module; HSM fleet runs escrow service for Secure Backup; public keys for authenticating the HSM services in /System/Library/Security/Certificates.bundle/Contents/Resources/AppleESCertificates.plist Hardware Security Module; HSM fleet runs escrow service for Secure Backup
164 Hyperion Hyperion iCloud Photos, uses CloudKit; launchd service: com.apple.cloudphotod; command line tool: cpldiagnose iCloud Photos, uses CloudKit; launchd service: com.apple.cloudphotod
165 IAP IAP iPod Accessory Protocol; IAP.framework iPod Accessory Protocol; IAP.framework
166 iBoot iBoot boot loader stage after boot ROM or UEFI (macOS on Intel); intermediate Low-Level Bootloader (LLB); DFU mode is implemented here; /System/Library/CoreServices/boot.efi boot loader stage after boot ROM or UEFI (macOS on Intel); intermediate Low-Level Bootloader (LLB); DFU mode is implemented here; /System/Library/CoreServices/boot.efi
167 iCDP iCDP iCloud Data Protection, codename for a set of enhancements to iCloud privacy: device passcodes used as iCSC for Secure Backup, root keys for CKKS-enabled services only synced between devices and not stored at Apple; launchd service: com.apple.cdpd iCloud Data Protection, codename for a set of enhancements to iCloud privacy: device passcodes used as iCSC for Secure Backup, root keys for CKKS-enabled services only synced between devices and not stored at Apple; launchd service: com.apple.cdpd
168 iCloud iCloud umbrella term for a conglomerate of services, consists of FoundationDB containers with PCS views for key management, supported by CKKS; uses IDS and APNS; some services under the iCloud name are actually served by AMS, IMAP, or DAV umbrella term for a conglomerate of services, consists of FoundationDB containers with PCS views for key management, supported by CKKS; uses IDS and APNS; some services under the iCloud name are actually served by AMS, IMAP, or DAV
169 iCSC iCSC iCloud Security Code, credential wrapping for Secure Backup, previously used a separate code, with HSA2/iCDP uses device passcodes iCloud Security Code, credential wrapping for Secure Backup, previously used a separate code, with HSA2/iCDP uses device passcodes
170 IDAM IDAM Inter-Device Audio and MIDI; audio connection between devices Inter-Device Audio and MIDI; audio connection between devices
171 IDS IDS Identity Service, also IDMS, Apple ID identity management for all of Apple’s online services; APNS topics for signaling and messaging, see also Alloy, ESS, FaceTime, iMessage; authentication to services with Kerberos Identity Directory Service, also IDMS, Apple Account identity management for all of Apple’s online services; APNS topics for signaling and messaging, see also Alloy, ESS, FaceTime, iMessage; authentication to services with Kerberos
172 IDV Identity Verification? Touch ID and Face ID; /System/Library/AccessibilityBundles/CoreIDVUI.axbundle
173 IM IM Instant Messaging; usually means iMessage and FaceTime Instant Messaging; usually means iMessage and FaceTime
174 IMG4 IMG4 boot files (Mach-O binaries or configuration data) with ASN.1 signature, contains RemotePolicy certificate constraints to restrict Boot Policy evaluation boot files (Mach-O binaries or configuration data) with ASN.1 signature, contains RemotePolicy certificate constraints to restrict Boot Policy evaluation
175 Intent Intent use-case-driven interaction with 3rd-party apps from a host app; used for Siri, Maps, Widgets (configuration); extension points: com.apple.intents-service, com.apple.intents-ui-service semantic interaction between app and system (or another app); used for Siri, Shortcuts, Maps (contextual suggestion), Widgets (configuration); definition by file or programmatically using AppIntents.framework; command line tool: appintentsmetadataprocessor (Xcode extracts Intent definition at compile time); extension points: com.apple.intents-service, com.apple.intents-ui-service
176 IOKit IOKit device driver subsystem for in-kernel and DriverKit drivers, command line tool: ioreg device driver subsystem for in-kernel and DriverKit drivers, command line tool: ioreg
177 Ironwood Ironwood dictation, customized on server with selected user data (contacts, app names, music titles, HomeKit names, Siri Shortcut phrases), not tied to Apple ID; SpeechRecognitionCore.framework; server: guzzoni.apple.com dictation, customized on server with selected user data (contacts, app names, music titles, HomeKit names, Siri Shortcut phrases), not tied to Apple Account; SpeechRecognitionCore.framework, ASRBridge.framework; server: guzzoni.apple.com
178 ISP ISP Image Signal Processor; camera imaging circuit in iPhones Image Signal Processor; camera imaging circuit in iPhones
179 ITML ITML iTunes Markup Language; metdata tagging for media services; ITMLKit.framework iTunes Markup Language; metdata tagging for media services; ITMLKit.framework
180 ITP ITP Intelligent Tracking Prevention, cross-site tracking defenses in Safari, statistics and user interaction classify sites, cookies are partitioned and access is restricted Intelligent Tracking Prevention, cross-site tracking defenses in Safari, statistics and user interaction classify sites, cookies are partitioned and access is restricted
181 JARVIS JARVIS Just A Rather Very Intelligent Scheduler, Mesos cluster manager for Siri, iCloud, AMS Just A Rather Very Intelligent Scheduler, Mesos cluster manager for Siri, iCloud, AMS
182 Jellyfish Jellyfish Animoji Animoji; /Applications/Jellyfish.app
183 Jetsam Jetsam reclaiming of purgeable memory and termination of apps during memory pressure reclaiming of purgeable memory and termination of apps during memory pressure
184 JSC JSC JavaScript Core; JavaScriptCore.framework; command line tool: jsc JavaScript Core; JavaScriptCore.framework; command line tool: jsc
185 Kalamata Kalamata codename for the transition from x86 to ARM-based Apple Silicon codename for the transition from x86 to ARM-based Apple Silicon
186 Kerberos Kerberos single-sign-on mechanism; Heimdal.framework; command line tools: kinit, ktutil single-sign-on mechanism; Heimdal.framework; command line tools: kinit, ktutil
187 Kext Kext kernel extension mechanism, loaded at boot time as part of a Kext Collection; /Library/Extensions, /Library/StagedExtensions (for user approval), /System/Library/Extensions; command line tool: kextutil (manages deprecated runtime loading) kernel extension mechanism, loaded at boot time as part of a Kext Collection; /Library/Extensions, /Library/StagedExtensions (for user approval), /System/Library/Extensions; command line tool: kextutil (manages deprecated runtime loading)
188 Kext Collection Kext Collection prelinked sets of kernel extensions; /System/Library/KernelCollections (for boot and system kexts), /Library/KernelCollections (for auxiliary third-party kexts); the latter is only loaded at a lower-security Boot Policy; launchd service: com.apple.kernelmanagerd (invoked by kernel through host special port 15); command line tool: kmutil prelinked sets of kernel extensions; /System/Library/KernelCollections (for boot and system kexts), /Library/KernelCollections (for auxiliary third-party kexts); the latter is only loaded at a lower-security Boot Policy; launchd service: com.apple.kernelmanagerd (invoked by kernel through host special port 15); command line tool: kmutil
189 Keybag Keybag storage of protection class keys for Keychain and filesystem, protected by SEP using SKP; stored in user.kb; launchd services: com.apple.mobile.keybagd, com.apple.securityd_service, com.apple.secd storage of protection class keys for Keychain and filesystem, protected by SEP using SKP; stored in user.kb; launchd services: com.apple.mobile.keybagd, com.apple.secd
190 Keychain Keychain storage for credentials; launchd service: com.apple.securityd; command line tools: certtool, security, systemkeychain storage for credentials; launchd service: com.apple.securityd; command line tools: certtool, security, systemkeychain
191 KIP KIP Kernel Integrity Protection, locking of physical memory pages to prevent changes to kernel Kernel Integrity Protection, locking of physical memory pages to prevent changes to kernel
192 Launch Services Launch Services management for application launches, association of UTIs to apps, uses Spotlight to update cached info; launchd services: com.apple.coreservices.launchservicesd, com.apple.lsd; CoreServices.framework/LaunchServices.framework; command line tools: lsappinfo, lsregister management for application launches, association of UTIs to apps, uses Spotlight to update cached info; launchd services: com.apple.coreservices.launchservicesd, com.apple.lsd; CoreServices.framework/LaunchServices.framework; command line tools: lsappinfo, lsregister
193 Live Files user mode filesystems, currently FAT, ExFAT, NTFS on external storage; UserFS.framework, UVFSXPCService.framework; launchd service: com.apple.filesystems.userfsd
194 Liverpool Liverpool PCS codename for CloudKit PCS codename for CloudKit
195 LKDC LKDC Local Key Distribution Center, Kerberos on client machines Local Key Distribution Center, Kerberos on client machines
196 LSM LSM Latent Semantic Mapping, text analysis, used for spam filtering, command line tool: lsm Latent Semantic Mapping, text analysis, used for spam filtering, command line tool: lsm
197 Mac Buddy Mac Buddy historic name for Setup Assistant historic name for Setup Assistant
198 MAC Policy MAC Policy Mandatory Access Control subsystem in XNU, based on TrustedBSD, implements policy hooks for restricted kernel operations; current policies: AMFI, Seatbelt, Quarantine, CSR Mandatory Access Control subsystem in XNU, based on TrustedBSD, implements policy hooks for restricted kernel operations; current policies: AMFI, Seatbelt, Quarantine, CSR
199 Machine Learning Machine Learning Vision.framework, Espresso.framework, Futhark.framework, PhotoAnalysis.framework Vision.framework, Espresso.framework, Futhark.framework, PhotoAnalysis.framework; used for Live Text and Visual Lookup; launchd service: com.apple.mediaanalysisd
200 Madrid Madrid iMessage; /System/Library/Messages iMessage; /System/Library/Messages
201 Manatee Manatee PCS key for some CloudKit containers are synced via CKKS, so data is unreadable to Apple (credential management codenames: Plesio, Stingray, Cuttlefish) PCS key for some CloudKit containers are synced via CKKS, so data is unreadable to Apple (credential management codenames: Plesio, Stingray, Cuttlefish)
202 Mandrake emergency siren on Apple Watch Ultra; /Applications/Mandrake.app
203 Mangrove Mangrove transfering UI tiles over XPC; Mangrove.framework, IOSurface.framework transfering UI tiles over XPC; Mangrove.framework, IOSurface.framework
204 Marco Marco Marco.framework, something about IDS and communication (iMessage, Calls), logging? Marco.framework, something about IDS and communication (iMessage, Calls), logging?
205 Marklar Marklar codename from the PowerPC era for the port to x86, served the transition to Intel CPUs codename from the PowerPC era for the port to x86, served the transition to Intel CPUs
206 MARRS Multimodal Reference Resolution; Marrs.framework
207 Marzipan Marzipan Catalyst; port of iOS frameworks to macOS, Catalyst apps are iOS apps with additional API to adapt macOS UI idioms; /System/iOSSupport; integration using UIKit system process; launchd service: com.apple.uikitsystemapp; input remapping by /Library/Apple/Library/Bundles/InputAlternatives.bundle Catalyst; port of iOS frameworks to macOS, Catalyst apps are iOS apps with additional API to adapt macOS UI idioms; /System/iOSSupport; integration using UIKit system process; launchd service: com.apple.uikitsystemapp; input remapping by /Library/Apple/Library/Bundles/InputAlternatives.bundle
208 MCX MCX Managed Client for OS X, preference management for settings from configuration profiles, /Library/Managed Preferences, command line tools: mcxquery, mcxrefresh Managed Client for OS X, preference management for settings from configuration profiles, /Library/Managed Preferences, command line tools: mcxquery, mcxrefresh
209 MDM MDM Mobile Device Management; server software to manage fleets of iOS and macOS devices; uses configuration profiles to manage preferences; ConfigurationProfiles.framework Mobile Device Management; server software to manage fleets of iOS and macOS devices; uses configuration profiles to manage preferences; ConfigurationProfiles.framework
210 MDS MDS Module Directory Services, ancient part of the old security APIs (CSDA, CSSM) Module Directory Services, ancient part of the old security APIs (CSDA, CSSM)
211 Memory Debugging Memory Debugging uses Taskport; command line tools: heap, leaks, malloc_history, stringdups, vmmap uses Taskport; command line tools: heap, leaks, malloc_history, stringdups, vmmap
212 Mesa Mesa Touch ID; /Library/Catacomb; /var/db/bkad.db Touch ID; /Library/Catacomb
213 Metadata Metadata Spotlight; file indexing on macOS; CoreServices.framework/Metadata.framework, CoreServices.framework/SearchKit.framework; stored in .Spotlight-V100; launchd service: com.apple.metadata.mds; command line tools: mddiagnose, mdfind, mdimport, mdls, mdutil; in addition to auto-indexing, apps can explicitly register searchable items; CoreSpotlight.framework; launchd service: com.apple.corespotlightd Spotlight; file indexing on macOS; CoreServices.framework/Metadata.framework, CoreServices.framework/SearchKit.framework; stored in .Spotlight-V100; launchd service: com.apple.metadata.mds; command line tools: mddiagnose, mdfind, mdimport, mdls, mdutil; in addition to auto-indexing, apps can explicitly register searchable items; CoreSpotlight.framework; launchd service: com.apple.corespotlightd
214 Micro Location positioning service on macOS (because there is no GPS?); MicroLocation.framework; launchd service: com.apple.milod
215 MLHost background machine learning service; launchd service: com.apple.mlhostd; /System/Library/MLHost; DeepThought.framework, LighthouseBackground.framework, LighthouseBitacoraFramework.framework, Dendrite.framework
216 MMCS MMCS MobileMe Chunk Storage, used by iCloud, splits blobs into chunks and stores them at Apple/AWS/GCP with convergent encryption (content hash as key); MMCS.framework MobileMe Chunk Storage, used by iCloud, splits blobs into chunks and stores them at Apple/AWS/GCP with convergent encryption (content hash as key); MMCS.framework
217 Mobile Mobile prefix for iOS prefix for iOS
218 Mobile Assets Mobile Assets demand-downloaded system components like fonts, dictionaries, linguistic data; stored in /System/Library/Assets; launchd services: com.apple.languageassetd (language-dependent assets), com.apple.mobileassetd; server: mesu.apple.com demand-downloaded system components like fonts, dictionaries, linguistic data; stored in /System/Library/Assets; launchd services: com.apple.languageassetd (language-dependent assets), com.apple.mobileassetd; server: mesu.apple.com
219 Mobile Device Mobile Device connectivity to iOS devices over USB or WiFi (AirTrafficHost) for syning, development, and debugging; MobileDevice.framework; launchd service: com.apple.usbmuxd; Bonjour service: _apple-mobdev2._tcp connectivity to iOS devices over USB or WiFi (AirTrafficHost) for syning, development, and debugging; MobileDevice.framework; launchd service: com.apple.usbmuxd; Bonjour service: _apple-mobdev2._tcp
220 MOC MOC Managed Object Context; Core Data object space Managed Object Context; Core Data object space
221 Mondrian Mondrian photo collage arrangement in Photos.app; Mondrian.framework photo collage arrangement in Photos.app; Mondrian.framework
222 MRT MRT Malware Removal Tool; /Library/Apple/System/Library/CoreServices/MRT.app Malware Removal Tool; /Library/Apple/System/Library/CoreServices/MRT.app; superseded by XProtect
223 Multipeer Connectivity Multipeer Connectivity ad-hoc networking; Bonjour for discovery; WiFi, AWDL, Bluetooth, or Ethernet as transport; optional encryption and certificate-based authentication; MultipeerConnectivity.framework ad-hoc networking; Bonjour for discovery; WiFi, AWDL, Bluetooth, or Ethernet as transport; optional encryption and certificate-based authentication; MultipeerConnectivity.framework
224 Nano Nano prefix for watchOS prefix for watchOS
225 Neural Engine Nearby Interaction hardware accelerator for neural network operations; ANECompiler.framework, ANEServices.framework; launchd service: com.apple.aned proximity-based interaction between devices; proximity measured using ultra wideband or derived from other technologies; used for Universal Control, tapping phones for AirDrop; NearbyInteraction.framework, Proximity.framework; launchd services: com.apple.aonsensed (always-on sense daemon), com.apple.nearbyd
226 Nebula sleep apnea detection on watchOS; BreathingAlgorithms.framework
227 Newton Newton fall detection on watchOS fall detection on watchOS
228 NLP NLP Natural Language Processing; NLP.framework; related to mecabra libraries, a linguistic engine for Chinese and Japanese; /usr/share/mecabra, /usr/share/tokenizer Natural Language Processing; NLP.framework; related to mecabra libraries, a linguistic engine for Chinese and Japanese; /usr/share/mecabra, /usr/share/tokenizer
229 Notarization Notarization app security scan by Apple; cryptographic proof stapled to code signature, tested at launch by System Policy; for non-notarized apps sends code hash to Apple; command line tools: altool, notarytool, stapler app security scan by Apple; cryptographic proof stapled to code signature, tested at launch by System Policy; for non-notarized apps sends code hash to Apple; command line tools: notarytool, altool, stapler
230 Noticeboard Noticeboard User Notifications for Software Update and App Store, Noticeboard.framework; launchd services: com.apple.noticeboard.state (nbstated), com.apple.noticeboard.agent (nbagent) User Notifications for Software Update and App Store, Noticeboard.framework; launchd services: com.apple.noticeboard.state (nbstated), com.apple.noticeboard.agent (nbagent)
231 Notifications Notifications system notification bus, unrelated to the local/remote push notifications; launchd service: com.apple.notifyd, com.apple.kuncd (invoked by kernel through host special port 10); command line tool: notifyutil; complemented by framework-level notification system (CFNotification, NSNotification); launchd services: com.apple.distnoted.xpc.daemon, com.apple.distnoted.xpc.agent system notification bus, unrelated to the local/remote push notifications; launchd service: com.apple.notifyd, com.apple.kuncd (invoked by kernel through host special port 10); command line tool: notifyutil; complemented by framework-level notification system (CFNotification, NSNotification); launchd services: com.apple.distnoted.xpc.daemon, com.apple.distnoted.xpc.agent
232 NSP NSP Network Service Proxy; per-app VPN and proxy settings, implements Private Relay; launchd service: com.apple.networkserviceproxy Network Service Proxy; per-app VPN and proxy settings, implements Private Relay; launchd service: com.apple.networkserviceproxy
233 OAH OAH Rosetta; /usr/libexec/rosetta Rosetta; ahead-of-time compiler for Intel code on Apple Silicon, usable from Linux VMs by way of a custom binformat; /usr/libexec/rosetta; launchd service: com.apple.oahd
234 ODR ODR On-Demand Resources; loaded from App Store; launchd service: com.apple.appstored On-Demand Resources; loaded from App Store; launchd service: com.apple.appstored
235 Omni Search fuzzy semantic search with results recognized in images; OmniSearch.framework
236 Onboarding Onboarding data protection splash screen shown by service-connected apps; /System/Library/OnBoardingBundles; OnBoardingKit.framework data protection splash screen shown by service-connected apps; /System/Library/OnBoardingBundles; OnBoardingKit.framework
237 Open Directory Open Directory directory service for user, group, and machine management; plugin-based to use different backend stores (LDAP, Active Directory), local accounts in /private/var/db/dslocal; launchd service: com.apple.opendirectoryd; command line tools: dscacheutil, dscl, dsconfigad, dsconfigldap, dseditgroup, dsenableroot, dserr, dsexport, dsimport, dsmemberutil, odutil directory service for user, group, and machine management; plugin-based to use different backend stores (LDAP, Active Directory), local accounts in /private/var/db/dslocal, populated from /System/Library/DirectoryServices/DefaultLocalDB; launchd service: com.apple.opendirectoryd; command line tools: dscacheutil, dscl, dsconfigad, dsconfigldap, dseditgroup, dsenableroot, dserr, dsexport, dsimport, dsmemberutil, odutil
238 OpenBSM Open Basic Security Module; deprecated security audit subsystem; /etc/security, /var/audit; launchd service: com.apple.auditd; command line tool: audit
239 Opus Opus create slide shows from photos; Slideshows.framework create slide shows from photos; Slideshows.framework
240 OSA OSA Open Scripting Architecture; scripting of applications from different fontend languages (currently AppleScript and JavaScript); backed by Apple Events; command line tools: osacompile, osadecompile, osalang, osascript, sdef, sdp Open Scripting Architecture; scripting of applications from different fontend languages (currently AppleScript and JavaScript); backed by Apple Events; command line tools: osacompile, osadecompile, osalang, osascript, sdef, sdp
241 OTUT OTUT One-Time Unlock Token; security mechanism to allow keybag unwrapping after updates One-Time Unlock Token; security mechanism to allow keybag unwrapping after updates
242 PAC PAC Pointer Authentication Codes; pointers signed in unused bits to prevent ROP attacks Pointer Authentication Codes; pointers signed in unused bits to prevent ROP attacks
243 Packages Packages unit of software installation; command line tools: pkgutil, installer, softwareupdate; launchd services: com.apple.softwareupdated, com.apple.bootinstalld, com.apple.installd, com.apple.system_installd, com.apple.uninstalld; /var/db/softwareupdate, /Library/Apple/System/Library/Receipts (system), /System/Library/Receipts (read-only), /private/var/db/receipts (App Store) unit of software installation; command line tools: pkgutil, installer, softwareupdate; launchd services: com.apple.softwareupdated, com.apple.bootinstalld, com.apple.installd, com.apple.system_installd, com.apple.uninstalld; /var/db/softwareupdate, /Library/Apple/System/Library/Receipts (system), /System/Library/Receipts (read-only), /private/var/db/receipts (App Store)
244 Parsec Packet Filter Spotlight web results and searching of crowdsourced User Activity deep links; server: *.smoot.apple.com; launchd services: com.apple.parsecd, com.apple.parsec-fbf (Feedback Flush to Differential Privacy) network traffic filtering subsystem from OpenBSD; command line tool: pfctl
245 Parsec Spotlight web results and searching of crowdsourced Intent deep links; server: *.smoot.apple.com; launchd services: com.apple.parsecd, com.apple.parsec-fbf (Feedback Flush to Differential Privacy); telemetry collection with Poirot: PoirotSQLite.framework, PoirotUDFs.framework, SearchOnDeviceAnalytics.framework
246 Party Studio Karaoke mode on tvOS, where video from a paired phone is shown with effects; /System/Library/PrivateFrameworks/PartyStudio.*
247 Passkey keypair used for authentication instead of password, synced via SOS, implements WebAuthn standard; keys can be used to login on separate device via QR code and Bluetooth proximity proof; AuthenticationServices.framework
248 Password Breach Password Breach monitoring of Keychain passwords against a breach database; round-robin matching in fixed-size batches, local match against common leaks, remote match using hash prefix; launchd service: com.apple.Safari.passwordbreachd monitoring of Keychain passwords against a breach database; round-robin matching in fixed-size batches, local match against common leaks, remote match using hash prefix; launchd service: com.apple.Safari.passwordbreachd
249 Pasteboard Pasteboard storage for cut, copy, and paste; type of content remembered as UTI; launchd service: com.apple.pboard; command line tools: pbcopy, pbpaste storage for cut, copy, and paste; type of content remembered as UTI; launchd service: com.apple.pboard; command line tools: pbcopy, pbpaste
250 PCS PAT Protected Cloud Storage; key management for separate iCloud storage compartments (PCS calls them views), each can contain FoundationDB plus bulk data stored by MMCS; see also iCDP, CKKS, Manatee; ProtectedCloudStorage.framework; /System/Library/Preferences/ProtectedCloudStorage; command line tool: pcsstatus Private Access Tokens; blind challenge-response authentication; Apple server attests user validity to token issuer, issuer performs blind signature, websites receiving the token cannot identify user; used for Private Relay, can replace CAPTCHAs
251 PCC Private Cloud Compute; server-based AFM for AI, running on Apple Silicon managed by SEP; stateless computation, PAT to authorize user, Attestation of remote code by device, measurements published in Transparency; ~/Library/PrivateCloudCompute; launchd services: com.apple.privatecloudcomputed, com.apple.swtransparencyd
252 PCS Protected Cloud Storage; key management for separate iCloud storage compartments (PCS calls them views), each can contain FoundationDB plus bulk data stored by MMCS; see also iCDP, CKKS, GroupKit, Manatee; ProtectedCloudStorage.framework; /System/Library/Preferences/ProtectedCloudStorage; command line tool: pcsstatus
253 PCSC PCSC Personal Computer Smart Card; PCSC.framework, uses CTK Personal Computer Smart Card; PCSC.framework, uses CTK
254 PDE PDE Print Dialog Extension; old name, not a proper Extension Print Dialog Extension; old name, not a proper Extension
255 Pegasus PEC/PIR picture-in-picture video playback; Pegasus.framework (iOS), PIP.framework (macOS) Private Encrypted Compute and Private Information Retrieval; used for parental controls for media and web; CipherML.framework; launchd service: com.apple.ciphermld
256 Pegasus meaning 1: picture-in-picture video playback; Pegasus.framework (iOS), PIP.framework (macOS); meaning 2: online search query engine for visual lookup; PegasusKit.framework
257 People contacts with Apple Accounts within Group Activities and Shared With You
258 Pepper Pepper UI elements for Watch home screen and Chat, like Quickboard (canned replies), Animoji; PepperUICore.framework UI elements for Watch home screen and Chat, like Quickboard (canned replies), Animoji; PepperUICore.framework
259 Persona Persona separation of sub-user-identities, like when using a private and managed Apple account; PersonaKit.framework; ~/Library/Personas; /System/Library/UserManagement; command line tool: umtool separation of sub-user-identities, like when using a private and managed Apple account; PersonaKit.framework; ~/Library/Personas; /System/Library/UserManagement; command line tool: umtool
260 PHASE PHASE spatial audio processing; PHASE.framework Physical Audio Spatialization Engine; 3D sound rendering engine; Apple devices map audio sources (even mono and stereo) to virtual speakers in a 3D sound stage, which is simulated by the physical speakers via a head-related transfer function; PHASE.framework
261 Piano Mover Piano Mover Mail Drop; bulk mail attachments transfered over PCS; not to be confused with storage for iMessage attachments, which uses a CloudKit container Mail Drop; bulk mail attachments transfered over PCS; not to be confused with storage for iMessage attachments, which uses a CloudKit container
262 Plugin Plugin Extensions, XPC services bundled with apps or frameworks, discovery by Launch Services; launchd service: com.apple.pluginkit.pkd; command line tool: pluginkit Extensions, XPC services bundled with apps or frameworks, discovery by Launch Services; extension points listed in /System/Library/ExtensionKit/ExtensionPoints; launchd service: com.apple.pluginkit.pkd; command line tool: pluginkit
263 PMC Performance Monitoring Counters; Recount.framework; /usr/share/kpep
264 PMP PMP Port Mapping Protocol; Apple alternative to UPnP, Bonjour service: _acp-sync._tcp Port Mapping Protocol; Apple alternative to UPnP, Bonjour service: _acp-sync._tcp
265 Poster iPhone lock screen; PosterBoard.framework, PosterKit.framework; /Library/Wallpaper
266 PowerUI PowerUI battery management like smart charge and power save, learns from Duet and other data; PowerUI.framework; /var/db/PowerUI; launchd service: com.apple.PowerUIAgent battery management like smart charge and power save, learns from Duet and other data; PowerUI.framework; /var/db/PowerUI; launchd service: com.apple.PowerUIAgent
267 Preferences Preferences storage for user-configurable settings; launchd services: com.apple.cfprefsd.xpc.daemon, com.apple.cfprefsd.xpc.agent; stored in Library/Preferences, command line tool: defaults; interaction with Synced Defaults per /System/Library/DefaultsConfigurations storage for user-configurable settings; launchd services: com.apple.cfprefsd.xpc.daemon, com.apple.cfprefsd.xpc.agent; stored in Library/Preferences, command line tool: defaults; interaction with Synced Defaults per /System/Library/DefaultsConfigurations
268 Private Relay Preview Shell two-hop onion routing with one entry and one exit node; Apple operates entry, third-party services operate exit nodes; approximate IP geolocation via Waldo skeleton for on-device UI previews during development; /System/Library/CoreServices/PreviewShell.app; PreviewShellKit.framework, XOJIT.framework (code live patching)
269 Proactive Private Relay umbrella term for suggestions and completions based on Duet forecasting and User Activity context, also marketed as Siri features; PersonalizationPortrait.framework two-hop onion routing with one entry and one exit node; Apple operates entry, third-party services operate exit nodes; QUIC for payload, ODoH for DNS, approximate IP geolocation via Waldo, authentication via PAT
270 Proactive umbrella term for suggestions, completions, and summarizations based on Duet forecasting, Biome, and Intent context; PersonalizationPortrait.framework, ProactiveMagicalMoments.framework, ProactiveSummarization.framework
271 Provenance per-file origin tracking, extended attribute com.apple.provenance stores ID into /var/db/SystemPolicyConfiguration/ExecPolicy
272 QoS Classes QoS Classes inheritable property for Activities; semantic priorities, influences scheduling parameters; initially set at user-level, priority inheritance within GCD queues and across XPC in kernel? inheritable property for Activities; semantic priorities, influences scheduling parameters; initially set at user-level, priority inheritance within GCD queues and across XPC in kernel?
273 Quagga Quagga framework for QR and barcode decoding; Quagga.framework framework for QR and barcode decoding; Quagga.framework
274 Quick Action Quick Action extension type for quick interaction with foreign content within a host app; extension points: com.apple.services, com.apple.ui-services extension type for quick interaction with foreign content within a host app; extension points: com.apple.services, com.apple.ui-services
275 Quick Look Quick Look file preview and thumbnail generation; comand line tool: qlmanage file preview and thumbnail generation; comand line tool: qlmanage
276 RAOP RAOP Remote Audio Output Protocol, AirPlay; Bonjour service: _raop._tcp Remote Audio Output Protocol, AirPlay; Bonjour service: _raop._tcp
277 Rapport Rapport device pairing by proximity using Alloy, with PIN entry, or using iCloud; once paired, devices can access services; used for HomeKit, HomePod, AirPlay, Home Sharing, SideCar; Rapport.framework; launchd service: com.apple.rapportd; Bonjour service: _companion-link._tcp device pairing by proximity using Alloy, with PIN entry, or using iCloud; once paired, devices can access services; used for HomeKit, HomePod, AirPlay, Home Sharing, SideCar; Rapport.framework, ProximityAppleIDSetup.framework; launchd service: com.apple.rapportd
278 RCS Rich Communication Services; messaging service in mobile networks, successor to SMS; IMRCSTransfer.framework; /System/Library/Messages/PlugIns/RCS.imservice
279 Recents Recents recently used items (not files) in various applications, synced with Synced Defaults; CoreRecents.framework, /System/Library/Recents; launchd service: com.apple.recentsd recently used items (not files) in various applications, synced with Synced Defaults; CoreRecents.framework, /System/Library/Recents; launchd service: com.apple.recentsd
280 Relevance Engine Relevance Engine backend for Siri suggestions (for example of Siri Shortcuts), Widget smart stacks (also Siri watch face); consumes Duet knowledge and app-provided timelines with relevance hints; /System/Library/RelevanceEngine; launchd service: com.apple.relevanced backend for Siri suggestions (for example of Siri Shortcuts), Widget smart stacks (also Siri watch face); consumes Duet knowledge and app-provided timelines with relevance hints; /System/Library/RelevanceEngine
281 Remote Pairing Mobile Device pairing without wired connection; RemotePairingDevice.framework; Bonjour services: _remotepairing._tcp, _remotepairing-manual-pairing._tcp
282 RemoteXPC RemoteXPC connection to a non-SoC-integrated SEP like Bridge; uses HTTP/2 over a network interface, Bridge connected over USB, secured using Attestation; RemoteServiceDiscovery.framework, TrustedAccessory.framework; launchd service: com.apple.remoted, com.apple.tracd; command line tool: remotectl connection to a non-SoC-integrated SEP like Bridge; uses HTTP/2 over a network interface, Bridge connected over USB, secured using Attestation; RemoteServiceDiscovery.framework, TrustedAccessory.framework; launchd service: com.apple.remoted, com.apple.tracd; command line tool: remotectl
283 Replicator notification sync from Companion iPhone, also drives remotely displayed live activities; ReplicatorServices.framework; launchd service: com.apple.replicatord
284 Revisions Revisions document autosave and auto-versioning; stored in .DocumentRevisions-V100; GenerationalStorage.framework; launchd service: com.apple.revisiond document autosave and auto-versioning; stored in .DocumentRevisions-V100; GenerationalStorage.framework; launchd service: com.apple.revisiond
285 Routine Routine frequently visited locations on iOS, interacts with Duet; launchd service: com.apple.routined frequently visited locations on iOS, interacts with Duet; launchd service: com.apple.routined
286 RTC RTC Real-time Telemetry and Crash reporting; RTCReporting.framework; launchd service: com.apple.rtcreportingd Real-time Telemetry and Crash reporting; RTCReporting.framework; launchd service: com.apple.rtcreportingd
287 RTKit operating system used on Apple Silicon for firmware of co-processors
288 RunningBoard RunningBoard runtime management of apps, paradigm: app as service process invoked by system, check-in by frameworks, handles process assertions (frontmost app, see App Nap), memory pressure (see Jetsam) and compute resources (GPU), replacement for TAL?; launchd service: com.apple.runningboardd; /System/Library/LifecyclePolicy, /System/Library/RunningBoard runtime management of apps, paradigm: app as service process invoked by system, check-in by frameworks, handles process assertions (frontmost app, see App Nap), memory pressure (see Jetsam) and compute resources (GPU), replacement for TAL?; launchd service: com.apple.runningboardd; /System/Library/LifecyclePolicy, /System/Library/RunningBoard
289 Safety Monitor Check In; short-term location sharing in iMessage until a destination is reached; /Applications/SafetyMonitorApp.app
290 SBPL SBPL Sandbox Profile Language; a TinyScheme-based embedded DSL for Seatbelt profiles Sandbox Profile Language; a TinyScheme-based embedded DSL for Seatbelt profiles
291 SCIP SCIP System Coprocessor Integrity Protection; like KIP, but for SEP, ISP, Motion coprocessor System Coprocessor Integrity Protection; like KIP, but for SEP, ISP, Motion coprocessor
292 Screen Reader Screen Reader VoiceOver and Braille; /System/Library/ScreenReader; ScreenReader.framework VoiceOver and Braille; /System/Library/ScreenReader; ScreenReader.framework
296 Seatbelt Seatbelt process sandbox by filtering system calls; profiles written in SBPL; /System/Library/Sandbox/Profiles, /usr/share/sandbox; default file access policy asks for TCC confirmation before access to folders with user data (like Documents) is allowed; command line tool: sandbox-exec; launchd service: com.apple.sandboxd (invoked by kernel through host special port 14 for logging) process sandbox by filtering system calls; profiles written in SBPL; /System/Library/Sandbox/Profiles, /usr/share/sandbox; default file access policy asks for TCC confirmation before access to folders with user data (like Documents) is allowed; command line tool: sandbox-exec; launchd service: com.apple.sandboxd (invoked by kernel through host special port 14 for logging)
297 Secure Backup Secure Backup escrow part of CKKS; escrow key individually wrapped with passcodes of trusted devices, stored in HSM to prevent brute forcing, uses SRP so passcodes are not visible to iCloud, limited number of recovery attempts; protocol called Lakitu, uses FollowUp; launchd service: com.apple.SecureBackupDaemon (com.apple.sbd); CloudServices.framework escrow part of CKKS; escrow key individually wrapped with passcodes of trusted devices, stored in HSM to prevent brute forcing, uses SRP so passcodes are not visible to iCloud, limited number of recovery attempts; protocol called Lakitu, uses FollowUp; launchd service: com.apple.SecureBackupDaemon (com.apple.sbd); CloudServices.framework
298 SEP SEP Secure Enclave Processor; dedicated ARM core for security services, runs L4/Darbat-based sepOS, inline encryption to DRAM, manages AES keys in storage DMA engine, factory-paired channels to Touch ID/Face ID hardware, Secure Element, Neural Engine; SEP can use but not read UID and GID keys; credential verification performed by hardware lockbox with retry count enforcement Secure Enclave Processor; dedicated ARM core for security services, runs L4/Darbat-based sepOS, inline encryption to DRAM, manages AES keys in storage DMA engine, factory-paired channels to Touch ID/Face ID hardware, Secure Element, Neural Engine; SEP can use but not read UID and GID keys; credential verification performed by hardware lockbox with retry count enforcement
299 Seymour Sequoia Apple Fitness+; workout videos integrated with Watch sensors; SeymourCore.framework translation; downloadable language models can run on-device; /Applications/SequoiaTranslator.app, Translation.framework
300 Seymour Apple Fitness+; workout videos integrated with Watch sensors; SeymourCore.framework, Blackbeard.framework (personalisation and workout programs)
301 SF Symbols scalable UI symbols; rendered with various color treatments; SFSymbols.framework
302 Shared File List lists of recently opened files from apps that are stored with Launch Services; command line tool: sfltool; also manages login items and app-installed background daemons
303 Shared With You collaboration features between apps and iMessage; content shared via iMessage is surfaced in apps (Swift Transferable protocol), content in apps can be collaboratively edited and connected to an iMessage group; collaborations are expressed by keys derived from participant device keys, padded with a number of random keys to prevent tracking of device count, a merkle tree of those keys is used to prove inclusion of a specific device to an app; SharedWithYou.framework
304 Sharing Sharing umbrella term for wireless proximity services: AirDrop, Continuity, Instant Hotspot, WiFi sharing; used by loginwindow for Watch unlock; Sharing.framework; launchd service: com.apple.sharingd; also serves connection sharing and remote disk umbrella term for wireless proximity services: AirDrop, Continuity, Instant Hotspot, WiFi sharing; used by loginwindow for Watch unlock; Sharing.framework; launchd service: com.apple.sharingd; also serves connection sharing and remote disk
305 Shazam Shazam music recognition service; ShazamKit.framework; launchd service: com.apple.shazamd audio (especially music) recognition service; ShazamKit.framework; launchd service: com.apple.shazamd; command line tool: shazam
306 Shoebox Shoebox Passbook Passbook
307 Sidecar Sidecar using iPhone/iPad as Mac accessory: camera for photos and scanning, annotations, external display over low-latency WiFi (llw interface) using avconferenced encoding; SidecarCore.framework; launchd services: com.apple.sidecar-display-agent (SidecarDisplayAgent), com.apple.sidecar-relay (SidecarRelay) using iPhone/iPad as Mac accessory: external camera and microphone (ContinuityCapture), camera for photos and scanning (DocumentCamera.framework), iPad as display over low-latency WiFi (llw interface) using avconferenced encoding; /Applications/Sidecar.app; SidecarCore.framework; launchd services: com.apple.sidecar-display-agent (SidecarDisplayAgent), com.apple.sidecar-relay (SidecarRelay)
308 Signpost Signpost telemetry API to report points of interest in code; launchd service: com.apple.signpost.signpost_reporter telemetry API to report points of interest in code; launchd service: com.apple.signpost.signpost_reporter
309 Simulator SIL running an iOS/tvOS/watchOS personality on macOS, uses sandboxing and a separate Mach bootstrap namespace for container-like isolation, command line tool: simctl Secure Indicator Light; microphone and camera indicator on iPads rendered in hardware
310 Simulator running an iOS/tvOS/watchOS personality on macOS, uses sandboxing and a separate Mach bootstrap namespace for container-like isolation; installable simulators as disk images in /Library/Developer/CoreSimulator/Images; command line tool: simctl
311 SIP SIP System Integrity Protection or rootless mode; collection of kernel-level security restrictions regarding file system modification, unsigned Kexts, Taskport access, NVRAM access, DTrace; /System/Library/Sandbox/rootless.conf; command line tool: csrutil, rootless-init System Integrity Protection or rootless mode; collection of kernel-level security restrictions regarding file system modification, unsigned Kexts, Taskport access, NVRAM access, DTrace; /System/Library/Sandbox/rootless.conf; command line tool: csrutil, rootless-init
312 Site Association signed files in .well-known directory on websites; equivalent to Entitlements for websites, associates domains with app IDs for Universal Links; command line tool: swcutil
313 SKP SKP Sealed Key Protection; measurement of system state (boot chain IMG4 manifests, BPR, Boot Policy data, UID key, user passcode) to derive Keybag keys Sealed Key Protection; measurement of system state (boot chain IMG4 manifests, BPR, Boot Policy data, UID key, user passcode) to derive Keybag keys
314 SKS SKS Secure Key Store; handling of keybag keys within the SEP Secure Key Store; handling of keybag keys within the SEP
315 SkyLight SkyLight WindowServer; SkyLight.framework WindowServer; SkyLight.framework
316 Skywalk Skywalk network subsystem in XNU, links together actual technologies (Bluetooth, WiFi, Thunderbolt) and interfaces/tunnels; transacts in nexus (for conduits) and agent (for endpoints) objects; DriverKit network drivers use Skywalk; command line tool: skywalkctl network subsystem in XNU, links together actual technologies (Bluetooth, WiFi, Thunderbolt) and interfaces/tunnels; transacts in nexus (for conduits) and agent (for endpoints) objects; DriverKit network drivers use Skywalk; command line tool: skywalkctl
317 SLC System-Level Cache, architectural feature of Apple Silicon; cache located within SoC at controllers for external DRAM, serves all compute units and stages transfers between them
318 Social Gaming Social Gaming Game Center; multiplayer gaming services on top of CloudKit, shared storage and low-latency multicast for multiplayer sessions; launchd service: com.apple.gamed Game Center; multiplayer gaming services on top of CloudKit, shared storage and low-latency multicast for multiplayer sessions; launchd service: com.apple.gamed
319 Sock Puppet Sock Puppet Watch interaction that requires Companion device Watch interaction that requires Companion iPhone
320 SOS SOS Secure Object Sync; syncing backend for iCloud Keychain, not to be confused with the emergency call feature; transferred items previously staged in Synced Defaults, now uses CKKS; launchd services: com.apple.secd (access to local keychain), com.apple.security.cloudkeychainproxy3 (connects to Synced Defaults), com.apple.security.keychain-circle-notification Secure Object Sync; syncing backend for iCloud Keychain, not to be confused with the emergency call feature; transferred items previously staged in Synced Defaults, for two-factor accounts in CKKS; launchd services: com.apple.secd (access to local keychain), com.apple.security.cloudkeychainproxy3 (connects to Synced Defaults), com.apple.security.keychain-circle-notification
321 SPI SPI System Private Interface; /System/Library/PrivateFrameworks System Private Interface; /System/Library/PrivateFrameworks
322 SpringBoard SpringBoard iOS home screen; like Dock (Launchpad, Mission Control, desktop picture), Control Center, SystemUIServer (menu extras icons), loginwindow (lock screen), and WindowServer (compositor) on macOS; /System/Library/CoreServices/SpringBoard.app, /Applications/PreBoard.app, BaseBoard.framework, FrontBoard.framework, SplashBoard.framework; launchd service: com.apple.backboardd (compositor) iOS home screen; like Dock (Launchpad, Mission Control, desktop picture), Control Center, SystemUIServer (menu extras icons), loginwindow (lock screen), and WindowServer (compositor) on macOS; /System/Library/CoreServices/SpringBoard.app, /Applications/PreBoard.app, BaseBoard.framework, FrontBoard.framework, SplashBoard.framework; launchd service: com.apple.backboardd (compositor)
323 SPRR SPRR Shadow Permission Remap Register? feature of Apple Silicon to dynamically reintepret page permissions Shadow Permission Remap Register? feature of Apple Silicon to dynamically reintepret page permissions
324 SPTM Secure Page Table Monitor; code with higher-than-kernel privileges (Trustzone Monitor?) protects page table modifications; deprivileged Trusted Execution Monitor (TXM) implements policy; successor to FPR/SPRR?
325 SRP SRP Secure Remote Password; standard cryptographic protocol for proving knowledge of a secret such that attackers cannot brute-force the secret; AppleSRP.framework Secure Remote Password; standard cryptographic protocol for proving knowledge of a secret such that attackers cannot brute-force the secret; AppleSRP.framework
326 SSO SSO Single Sign-On Single Sign-On
327 SSV SSV Signed System Volume, als called Authenticated Root Volume (ARV); macOS boots from blessed read-only APFS snapshot, merkle-tree and root-hash stored in Preboot volume; modifications require disabling root authentication with csrutil from recovery, then the live filesystem can be mounted, modified, and re-blessed; command line tools: apfs_systemsnapshot, bless, csrutil Signed System Volume, als called Authenticated Root Volume (ARV); macOS boots from blessed read-only APFS snapshot, merkle-tree and root-hash stored in Preboot volume; modifications require disabling root authentication with csrutil from recovery, then the live filesystem can be mounted, modified, and re-blessed; command line tools: apfs_systemsnapshot, bless, csrutil
328 Stark Stark CarPlay CarPlay; iPhone provides video feeds for in-car displays; three layers composited by the car: remote UI (from iPhone), punch-through UI (back up camera), local UI (dashboard gauges: assets from iPhone, rendered by car, like Live Activities?), overlay UI (essential indicators); associate apps on iOS: /Applications/AutoSettings.app, /Applications/CarCamera.app, /Applications/Charge.app, /Applications/Climate.app, /Applications/Closures.app, /Applications/Media.app, /Applications/TirePressure.app, /Applications/Trip.app
329 Stockholm Stockholm Secure Element in Apple SoCs, a processor running crypto protocols on keys it protects; used for Apple Pay and Car Key; related codenames: Icefall, Warsaw Secure Element in Apple SoCs, a processor running crypto protocols on keys it protects; used for Apple Pay and Car Key; related codenames: Icefall, Warsaw
330 Storage Management Storage Management freeing up disk space by managing bulky items; UI in System Information.app; StorageManagement.framework; launchd service: com.apple.diskspaced; extension point: com.apple.storagemanagement; extends Cache Delete service freeing up disk space by managing bulky items; UI in System Information.app; StorageManagement.framework; launchd service: com.apple.diskspaced; extension point: com.apple.storagemanagement; extends Cache Delete service
331 Suggestions Suggestions semantic analysis of mails and websites to suggest contacts, calendar events and the like; launchd services: com.apple.suggestd, com.apple.reversetemplated; custom JavaScript parsers in /System/Library/AssetsV2/com_apple_MobileAsset_CoreSuggestions semantic analysis of mails and websites to suggest contacts, calendar events and the like; launchd services: com.apple.suggestd, com.apple.reversetemplated; custom JavaScript parsers in /System/Library/AssetsV2/com_apple_MobileAsset_CoreSuggestions
332 Symbols Symbols debug symbols for backtraces; CoreSymbolication.framework; launchd services: com.apple.coresymbolicationd; command line tools: symbols, symbolscache debug symbols for backtraces; CoreSymbolication.framework; launchd services: com.apple.coresymbolicationd; command line tools: atos, symbols, symbolscache
333 Symptoms Symptoms network diagnostics; Symptoms.framework; /var/networkd/db/netusage.sqlite; launchd service: com.apple.symptomsd (invoked by kernel through host special port 27) network diagnostics; Symptoms.framework; /var/networkd/db/netusage.sqlite; launchd service: com.apple.symptomsd (invoked by kernel through host special port 27)
334 Synced Defaults Synced Defaults simple key-value store for applications, no user control over data; can use iCloud key-value backend (old) or Manatee container (new, marked as com.apple.kvs) as storage; launchd service: com.apple.syncdefaultsd; locally stored in ~/Library/SyncedPreferences simple key-value store for applications, no user control over data; can use iCloud key-value backend (old) or Manatee container (new, marked as com.apple.kvs) as storage; launchd service: com.apple.syncdefaultsd; locally stored in ~/Library/SyncedPreferences
335 System Configuration System Configuration SystemConfiguration.framework; launchd service: com.apple.configd; command line tool: scutil SystemConfiguration.framework; launchd service: com.apple.configd; command line tool: scutil
336 System Extension System Extension user-level components formerly in the kernel; currently either a DriverKit, Network, or Endpoint Security extension; /System/DriverKit, /System/Library/DriverExtensions; command line tool: systemextensionsctl; launchd services: com.apple.sysextd, com.apple.nesessionmanager, com.apple.endpointsecurity.endpointsecurityd system-wide components formerly implemented as insecure plugins or kexts; current extension types: DriverKit, FSKit, Network, Endpoint Security, Core Media IO; /System/DriverKit, /System/Library/DriverExtensions, /Library/Preferences/com.apple.networkextension.plist; command line tool: systemextensionsctl; launchd services: com.apple.sysextd, com.apple.nesessionmanager, com.apple.endpointsecurity.endpointsecurityd; command line tool: eslogger
337 System Policy System Policy Gatekeeper; policy engine for application launches and kext loading, malware signatures from /Library/Apple/System/Library/CoreServices/XProtect.bundle; /var/db/SystemPolicy; launchd service: com.apple.security.syspolicy (invoked by kernel through host special port 29); command line tool: spctl Gatekeeper; policy engine for application launches and kext loading, malware signatures from /Library/Apple/System/Library/CoreServices/XProtect.bundle; /var/db/SystemPolicyConfiguration; launchd service: com.apple.security.syspolicy (invoked by kernel through host special port 29); command line tool: spctl
338 Tailspin sampling of process stack traces; launchd service: com.apple.tailspind; command line tool: tailspin
339 TAL TAL Transparent App Lifecycle; process for macOS apps started and stopped independently of the user launching and quitting app; also handles session restore across reboots; ~/Library/Saved Application State; launchd service: com.apple.talagent Transparent App Lifecycle; process for macOS apps started and stopped independently of the user launching and quitting app; also handles session restore across reboots; ~/Library/Saved Application State; launchd service: com.apple.talagent
340 Taskport Taskport Mach kernel concept for ptrace-like access to task internals; access policy implemented by daemon; launchd service: com.apple.taskgated (invoked by kernel through task special port 9); command line tool: DevToolsSecurity Mach kernel concept for ptrace-like access to task internals; access policy implemented by daemon; launchd service: com.apple.taskgated (invoked by kernel through task special port 9); command line tool: DevToolsSecurity
341 TCC TCC Transparency, Consent, and Control; user control over app access to privacy-related services (kTCCService*); TCC.framework; launchd services: com.apple.tccd, com.apple.tccd.system; command line tool: tccutil; stored in /Library/Application Support/com.apple.TCC, ~/Library/Application Support/com.apple.TCC, /var/db/locationd (for kTCCServiceLocation) Transparency, Consent, and Control; user control over app access to privacy-related services (kTCCService*); TCC.framework; launchd services: com.apple.tccd, com.apple.tccd.system; command line tool: tccutil; stored in /Library/Application Support/com.apple.TCC, ~/Library/Application Support/com.apple.TCC, /var/db/locationd (for kTCCServiceLocation)
342 Template App code-less app-bundle, passed to an actual executable by LauncServices; created when adding websites in Safari to Dock/Springboard; run by /System/Volumes/Preboot/Cryptexes/App/System/Library/CoreServices/Web App.app
343 Time Machine Time Machine automatic backup service, command line tools: tmdiagnose, tmutil automatic backup service, command line tools: tmdiagnose, tmutil
344 Tin Can Tin Can Walkie Talkie on watchOS Walkie Talkie on watchOS; /Applications/TinCan.app
345 Tones Tones ringtones; ToneLibrary.framework ringtones; ToneLibrary.framework
346 Translocation Translocation app binary copied on launch to dedicated location; initiated by Launch Services for security (prevents path traversal for apps quarantined by System Policy) or path normalization (iOS apps do not expect to be moved, but can be moved on macOS) app binary copied on launch to dedicated location; initiated by Launch Services for security (prevents path traversal for apps quarantined by System Policy) or path normalization (iOS apps do not expect to be moved, but can be moved on macOS)
347 Transparency Transparency key transparency for ESS keys? Transparency.framework; launchd service: com.apple.transparencyd; server: init-kt.apple.com un-alterable append-only log to publish information; used for for ESS keys and PCC software hashes, based on CONIKS, devices audit IDS/PCC records against logs, root hashes gossiped over iMessage to detect split-view attacks; Transparency.framework; launchd service: com.apple.transparencyd; server: init-kt.apple.com
348 TTS TSS Text To Speech, command line tool: say; /System/Library/Speech; synthesizer engines: MacinTalk (historic), Polyglot (phoneme-based?), Gryphon (current, DNN-based?) Tatsu Signing Server; online verification for firmware signatures; server: gs.apple.com
349 TTS Text To Speech, neural-network-based synthesis engine (Gryphon); command line tool: say; /System/Library/Speech, /System/Library/TTSPlugins
350 TVML TVML TV Markup Language; declarative UI language for TV apps; TVMLKit.framework TV Markup Language; declarative UI language for TV apps; TVMLKit.framework
351 Ubiquity UARP iCloud Drive; codename Bladerunner, uses CloudKit; CloudDocs.framework; command line tools: fileproviderctl; launchd service: com.apple.bird (iclouddrive-agent); locally stored in ~/Library/Mobile Documents (was supposed to move to Library/CloudStorage/iCloud Drive and iclouddrivectl but this was reverted) Universal Accessory Restore Protocol; CoreUARP.framework; launchd service: com.apple.uarppersonalizationd (personalized firmware)
352 Ubiquity iCloud Drive; codename Bladerunner, uses CloudKit; CloudDocs.framework; launchd service: com.apple.bird; locally stored in ~/Library/Mobile Documents (was supposed to move to Library/CloudStorage/iCloud Drive but this was reverted)
353 UID UID unique ID key, used as root key for cryptographic subsystems, generated during manufacturing by SEP and fused into hardware, only accessible by SEP unique ID key, used as root key for cryptographic subsystems, generated during manufacturing by SEP and fused into hardware, only accessible by SEP
354 Unified Logging Unified Logging system-wide logging and Activity tracking; launchd service: com.apple.logd, com.apple.diagnosticd; command line tool: log; /dev/oslog; data stored in /var/db/diagnostics, support files in /var/db/uuidtext system-wide logging and Activity tracking; launchd service: com.apple.logd, com.apple.diagnosticd; command line tool: log; /dev/oslog; data stored in /var/db/diagnostics, support files in /var/db/uuidtext
355 User Activity Urchin abstraction behind deep-linking into apps with structured context data (people, places); used for Universal Links (with schema.org on websites), Handoff, Parsec, Siri Shortcuts, Proactive; UserActivity.framework; launchd service: com.apple.coreservices.useractivityd Tides app on watchOS; /Applications/Urchin.app
356 USD Universal Scene Description; storage format for 3D assets; /usr/lib/usd; command line tools: usdcat, usdchecker, usdcrush, usdextract, usdrecord, usdtree, usdzip
357 User Activity abstraction for deep-linking into apps with structured context (people, places); used for Universal Links (schema.org on websites), Handoff, Parsec (app links in search), Quick Note (context awareness); now part of Intents; UserActivity.framework; launchd service: com.apple.coreservices.useractivityd
358 User Notifications User Notifications user interface for notification center; launchd service: com.apple.usernoted user interface for notification center; launchd service: com.apple.usernoted
359 UTI UTI Uniform Type Identifiers; system for document types; file extensions and MIME types are mapped to UTIs, UTIs form a conformance graph, apps register their UTIs with Launch Services; /System/Library/CoreServices/CoreTypes.bundle; also Apple’s hardware devices are represented as UTIs Uniform Type Identifiers; system for document types; file extensions and MIME types are mapped to UTIs, UTIs form a conformance graph, apps register their UTIs with Launch Services; /System/Library/CoreServices/CoreTypes.bundle; also Apple’s hardware devices are represented as UTIs
360 VA VA Video Acceleration; AppleGVA.framework, AppleVA.framework, AppleVPA.framework Video Acceleration; AppleGVA.framework, AppleVA.framework, AppleVPA.framework
361 VDAF Verifiable Distributed Aggregation Function; part of Differential Privacy; VDAF.framework
362 Viceroy Viceroy video conferencing used by FaceTime and ReplayKit; ViceroyTrace.framework video conferencing used by FaceTime and ReplayKit; ViceroyTrace.framework
363 Virtualisation running virtual machines on macOS; Hypervisor.framework (for basic VMs and vCPUs), Virtualization.framework (brings a robust set of device models)
364 VSDB VSDB volume status database; /var/db/volinfo.database; command line tool: vsdbutil volume status database; /var/db/volinfo.database; command line tool: vsdbutil
365 Waldo Waldo selects edge servers based on approximate location, part of Private Relay, seen in NSP selects edge servers based on approximate location, part of Private Relay, seen in NSP
366 WFS WFS WebDAV File Sharing; built-in file sharing with Apache; /etc/wfs; command line tool: wfsctl WebDAV File Sharing; built-in file sharing with Apache; /etc/wfs; command line tool: wfsctl
367 Widgets Widgets content excerpt from apps; provided via a timeline of view hierarchies, configuration uses Intents, technically very similar to complications on watch face; extension point: com.apple.widgetkit-extension content excerpt from apps; provided via a timeline of view hierarchies, configuration uses Intents; visible on home screen, lock screen, as live activities, as watch complications; WidgetKit.framework, ChronoServices.framework; extension point: com.apple.widgetkit-extension; launchd service: com.apple.chronod (timeline management and sync)
368 Willow Willow HomeKit; end-to-end-encrypted communication protocol and API for IoT-accessories; pairing with SRP using code printed on device, credential sync by CKKS, transported over Alloy, remote access using Apple TV as proxy; launchd service: com.apple.homed HomeKit; end-to-end-encrypted communication protocol and API for IoT-accessories; pairing with SRP using code printed on device, credential sync by CKKS, transported over Alloy, remote access using Apple TV as proxy; launchd service: com.apple.homed
369 Workflow Window Manager Shortcuts; user-programmable system-wide automation, built-in triggers and actions, extensible with User Activities and Intents; WorkflowKit.framework, ActionKit.framework; locally stored in ~/Library/Shortcuts; launchd service: com.apple.siriactionsd (voice-triggered shortcuts); command line tool: shortcuts implements Stage Manager; /System/Library/CoreServices/WindowManager.app; launchd service: com.apple.WindowManager.agent
370 Workflow Shortcuts; user-programmable system-wide automation, built-in triggers cause a chain of actions to run; actions are synthesized from User Activities and Intents provided by apps; WorkflowKit.framework, ActionKit.framework; locally stored in ~/Library/Shortcuts; launchd service: com.apple.siriactionsd (voice-triggered shortcuts); command line tool: shortcuts
371 xART xART eXtended Anti-Replay Technology; persistent storage for SEP, used by Mesa; /System/Volumes/xarts; launchd service: com.apple.xartstorageremoted; command line tool: xartutil eXtended Anti-Replay Technology; persistent storage for SEP, used by Mesa; /System/Volumes/xarts; launchd service: com.apple.xartstorageremoted; command line tool: xartutil
372 XCS XCS Xcode Server; continuous integration server; command line tools: xcscontrol, xcsdiagnose Xcode Server; continuous integration server; command line tools: xcscontrol, xcsdiagnose
373 XProtect signature-based malware scanner and remediation service; /Library/Apple/System/Library/CoreServices/XProtect.bundle; command line tool: xprotect