56 Commits

Author SHA1 Message Date
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
Michael Roitzsch
5e92d0e636 internals: update for macOS 12.1 Monterey 2021-11-22 14:11:48 +01:00
Michael Roitzsch
33947b2f46 Makefile: test for tool build errors 2021-11-08 10:44:59 +01:00
Michael Roitzsch
81f318f1e1 flake: fix acextract build (again) 2021-11-08 10:38:11 +01:00
Michael Roitzsch
07288c72e1 flake: update Xcode version 2021-11-08 10:37:33 +01:00
Michael Roitzsch
f3150df424 Makefile: fix entitlements export for Monterey 2021-10-29 19:52:30 +02:00
Michael Roitzsch
ef992d99d1 flake: enable snapshot reverting
snapUtil -r
2021-10-25 12:04:53 +02:00
Michael Roitzsch
28560df58f flake: fix Swift compiler crash 2021-10-25 12:03:31 +02:00
Michael Roitzsch
31fcb59c80 Makefile: extract DriverKit dyld cache 2021-10-25 12:03:31 +02:00
Michael Roitzsch
2deea7c208 flake: Monterey-compatible dyld cache extractor 2021-10-25 12:03:12 +02:00
Michael Roitzsch
563347a6db Makefile: assume a flake-capable Nix is installed 2021-10-20 10:43:55 +02:00
Michael Roitzsch
345d5a24c0 Makefile: configurable Xcode installation 2021-10-20 10:43:55 +02:00
Michael Roitzsch
40216ef6d4 flake: use unstable branch of nixpkgs 2021-10-20 10:43:55 +02:00
Michael Roitzsch
f79226a965 flake: use attribute naming convention, add lock 2021-10-20 10:43:55 +02:00
Michael Roitzsch
2cec40761a internals: update for macOS 11.4 2021-05-25 10:32:25 +02:00
Michael Roitzsch
1036b6326c Makefile: renew database if current system is newer 2021-05-25 10:31:22 +02:00
Michael Roitzsch
cfd54c9d8c flake: update to Xcode 12.5 2021-04-28 10:52:32 +02:00
Michael Roitzsch
30bdc30392 internals: update for macOS 11.3 2021-04-24 14:22:02 +02:00
Michael Roitzsch
aeae2a6157 Makefile: use most current compressed database 2021-04-24 14:21:31 +02:00
Michael Roitzsch
73de585019 flake: unquoted URLs are deprecated 2021-03-30 21:24:32 +02:00
Michael Roitzsch
9dfebf24ff internals: update with February 2021 security info 2021-03-28 10:00:00 +02:00
Michael Roitzsch
924e53e9b6 Makefile: tolerate errors with interactive SQlite 2021-03-27 16:01:19 +01:00
Michael Roitzsch
7ad7ac85f2 improve interactive SQLite completions
rename index to avoid it having the same prefix as the files table
2021-03-24 19:52:38 +01:00
Michael Roitzsch
b84e3ba5cf clear extended attributes 2021-03-24 18:07:00 +01:00
Michael Roitzsch
eaba592bcc handle URL fragment as search term
allows direct linking to specific searches
2021-03-11 10:02:40 +01:00
Michael Roitzsch
c26b374f48 update Xcode and fix crash in snapUtil 2021-02-22 09:37:29 +01:00
Michael Roitzsch
7bfdb02cc9 add a textual database dump of most relevant info
useful for diffing databases of multiple OS versions against each other
2020-12-31 18:41:47 +01:00
Michael Roitzsch
320cee87e0 fix passing DB as command line variable 2020-12-31 18:12:51 +01:00
Michael Roitzsch
23f5c368e0 better Nix flakes documentation link 2020-12-31 17:26:04 +01:00
Michael Roitzsch
f85006a1c9 convenience target for interactive database access 2020-12-31 17:25:47 +01:00
Michael Roitzsch
2128e5251f update to Xcode 12.3 2020-12-31 17:25:21 +01:00
Michael Roitzsch
6306ad242c document SQLite database and internals check 2020-11-24 19:37:06 +01:00
6 changed files with 489 additions and 204 deletions

104
Makefile
View File

@@ -1,16 +1,18 @@
override DB := $(if $(DB),$(DB:.lz=),$(lastword $(sort internals-$(shell sw_vers -productVersion).db $(basename $(wildcard internals-*)))))
MY_INTERNALS = $(HOME)/Library/Mobile\ Documents/com~apple~TextEdit/Documents/Apple\ Internals.rtf
DB := $(if $(DB),$(DB:.lz=),internals-$(shell sw_vers -productVersion).db)
DB_TARGETS = db_files db_binaries db_manifests db_assets db_services
CHECK_TARGETS = check_files check_binaries check_manifests check_services
.PHONY: all check $(DB_TARGETS) $(CHECK_TARGETS)
.PHONY: all check view sqlite $(DB_TARGETS) $(CHECK_TARGETS)
.INTERMEDIATE: $(DB)
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 $@
endif
ifneq ($(wildcard $(DB).lz),)
@@ -26,41 +28,65 @@ $(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
SELECT path,os FROM files;
SELECT path,os,name FROM files NATURAL JOIN assets;
SELECT path,os,dylib FROM files NATURAL JOIN linkages;
SELECT files.path,os,key,value FROM files NATURAL JOIN services, json_each(plist);
SELECT files.path,os,key,value FROM files NATURAL JOIN entitlements, json_each(plist);
endef
export VIEW
view: $(DB)
echo "$$VIEW" | sqlite3 -bail $< | LC_COLLATE=C sort
sqlite: $(DB)
sqlite3 $< || true
# MARK: - data extraction helpers
NIX = $(shell nix-build --no-out-link -A nixFlakes '<nixpkgs>')/bin/nix
ACEXTRACT = $(shell \
$(NIX) --experimental-features 'nix-command flakes' build --no-write-lock-file .\#acextract && \
ACEXTRACT = $(shell nix build --no-write-lock-file --no-warn-dirty .\#acextract && \
readlink result && rm result)/bin/acextract
DSCU = $(shell \
$(NIX) --experimental-features 'nix-command flakes' build --no-write-lock-file .\#dyld-shared-cache && \
readlink result && rm result)/bin/dyld_shared_cache_util
DSCEXTRACTOR = $(shell nix build --no-write-lock-file --no-warn-dirty .\#dsc-extractor && \
readlink result && rm result)/bin/dyld-shared-cache-extractor
dyld: /System/Library/dyld/dyld_shared_cache_$(shell uname -m)
$(DSCU) -extract $@ $<
$(DB_TARGETS)::
# evaluate helper tools to catch Nix build errors early
: $(ACEXTRACT)
: $(DSCEXTRACTOR)
dyld: /System/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_x86_64h /System/Cryptexes/OS/System/DriverKit/System/Library/dyld/dyld_shared_cache_x86_64h
if ! test -x $(DSCEXTRACTOR) ; then \
printf '\033[1mdscextractor tool unavailable\033[m\n' >&2 ; \
echo 'FAIL;' ; \
exit 1 ; \
fi
for i in $+ ; do $(DSCEXTRACTOR) $$i $@ ; done > /dev/null
find $@ -type f -print0 | xargs -0 chmod a+x
XCODE = $(lastword $(wildcard /Applications/Xcode.app /Applications/Xcode-beta.app))
prefix = $$(case $(1) in \
(macOS) ;; \
(macOS-dyld) echo $(dir $(realpath $(firstword $(MAKEFILE_LIST))))/dyld ;; \
(iOS) echo /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot ;; \
(tvOS) echo /Applications/Xcode.app/Contents/Developer/Platforms/AppleTVOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/tvOS.simruntime/Contents/Resources/RuntimeRoot ;; \
(watchOS) echo /Applications/Xcode.app/Contents/Developer/Platforms/WatchOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/watchOS.simruntime/Contents/Resources/RuntimeRoot ;; \
(iOS) echo $(wildcard /Library/Developer/CoreSimulator/Volumes/iOS_*/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS*.simruntime/Contents/Resources/RuntimeRoot) ;; \
(tvOS) echo $(wildcard /Library/Developer/CoreSimulator/Volumes/tvOS_*/Library/Developer/CoreSimulator/Profiles/Runtimes/tvOS*.simruntime/Contents/Resources/RuntimeRoot) ;; \
(watchOS) echo $(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 /Applications/Xcode.app/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)" ; 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 /' ; \
}
file = SELECT id, $(1) FROM files WHERE os = '$$os' AND path = '$$(echo "$$path" | sed "s/'/''/g")'
@@ -83,7 +109,7 @@ db_files:: dyld
echo 'CREATE TABLE files (id INTEGER PRIMARY KEY, os TEXT, path TEXT, executable BOOLEAN);'
$(call find,,sudo) | sed -E "s/'/''/g;s/([^ ]*) (.*)/INSERT INTO files (os, path) VALUES('\1', '\2');/"
find $(HOME)/Library | sed "s|^$(HOME)|~|;s/'/''/g;s/.*/INSERT INTO files (os, path) VALUES('macOS', '&');/"
echo 'CREATE INDEX files_path ON files (path);'
echo 'CREATE INDEX _files_path ON files (path);'
db_binaries:: dyld
printf '\033[1mcollecting executable information...\033[m\n' >&2
@@ -98,8 +124,8 @@ db_binaries:: dyld
if test -r "$(call prefix,$$os)$$path" && file --no-dereference --brief --mime-type "$(call prefix,$$os)$$path" | grep -Fq application/x-mach-binary ; then \
objdump --macho --dylibs-used "$(call prefix,$$os)$$path" | \
sed "1d;s/^.//;s/ ([^)]*)$$//;s/'/''/g;s|.*|INSERT INTO linkages $(call file,'&');|" ; \
codesign --display --entitlements - "$(call prefix,$$os)$$path" 2> /dev/null | \
sed 1d | plutil -convert json - -o - | \
codesign --display --xml --entitlements - "$(call prefix,$$os)$$path" 2> /dev/null | \
plutil -convert json - -o - | \
sed "/^<stdin>: Property List error/d;/^{}/d;s/'/''/g;s|.*|INSERT INTO entitlements $(call file,json('&'));\n|" ; \
strings -n 8 "$(call prefix,$$os)$$path" | \
LANG=C sed "s/'/''/g;s|.*|INSERT INTO strings $(call file,'&');|" ; \
@@ -114,8 +140,24 @@ db_manifests::
test -r "$(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 \
printf '\033[1macextract tool unavailable\033[m\n' >&2 ; \
echo 'FAIL;' ; \
exit 1 ; \
fi
printf '\033[1mcollecting asset catalog information...\033[m\n' >&2
echo 'DROP TABLE IF EXISTS assets;'
echo 'CREATE TABLE assets (id INTEGER REFERENCES files, name TEXT);'
@@ -138,15 +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/ \(.*\)$$//;s/^\/(etc|var)\//\/private&/' | \
sed "s/'/''/g;s|.*|SELECT count(*), '&' FROM files WHERE path GLOB '&';|" | \
sqlite3 $(DB) | sed -n "/^0|/{s/^0|//;p;}"
check_binaries: internals.txt $(DB)
check_binaries: internals.tsv $(DB)
printf '\033[1mchecking command line tools...\033[m\n' >&2
grep -o 'command line tools\?: [^;]*' $< | sed 's/^[^:]*: //;s/ //g;s/([^)]*)//g' | tr , '\n' | \
sed "s/'/''/g;s|.*|SELECT count(*), '&' FROM files WHERE executable = true AND path GLOB '*/&';|" | \
@@ -160,13 +202,13 @@ check_binaries: internals.txt $(DB)
sed "s/'/''/g;s/.*/SELECT count(*), '&' FROM strings WHERE string GLOB '*&*';/" | \
sqlite3 $(DB) | sed -n "/^0|/{s/^0|//;p;}"
check_manifests: internals.txt $(DB)
check_manifests: internals.tsv $(DB)
printf '\033[1mchecking extension points...\033[m\n' >&2
grep -o 'extension points\?: [^;]*' $< | sed 's/^[^:]*: //;s/ //g;s/([^)]*)//g' | tr , '\n' | \
sed "s/'/''/g;s|.*|SELECT count(*), '&' FROM info, json_each(plist, '$$.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 = '&';|" | \

View File

@@ -4,8 +4,8 @@ Apple Internals
This repository provides tools and information to help understand and analyze the internals
of Apples operating system platforms. Information is collected in a text file and
[presented on a website](https://mroi.github.io/apple-internals). A [Nix
flake](https://github.com/tweag/rfcs/blob/flakes/rfcs/0049-flakes.md) allows to build the
following externally hosted tools:
flake](https://nixos.wiki/wiki/Flakes) allows to build the following externally hosted
tools:
[**acextract**](https://github.com/bartoszj/acextract)
Unpacks asset catalogs to individual files.
@@ -16,6 +16,16 @@ Extracts dynamic libraries from the dyld linker cache.
[**snapUtil**](https://github.com/ahl/apfs)
Manages APFS snapshots.
The Makefile aggregates various kinds of information from the system in a SQLite database
and checks the internals text file against this information. Collected details include:
* all file names of the installed macOS and the iOS, tvOS, and watchOS simulators
* linkages of binaries to libraries
* entitlements for all executables
* plain-text strings embedded in binaries
* launchd service descriptions and bundle Info.plist content
* lists of assets inside asset catalogs
___
This work is licensed under the [MIT license](https://mit-license.org) so you can freely use
and share as long as you retain the copyright notice and license text.

93
flake.lock generated Normal file
View File

@@ -0,0 +1,93 @@
{
"nodes": {
"acextract": {
"flake": false,
"locked": {
"lastModified": 1556467432,
"narHash": "sha256-Yh437j5HLwh+s2qBKo3YruBHSJxqH142LuM/Unf+rV4=",
"owner": "bartoszj",
"repo": "acextract",
"rev": "df3b018d53cd4b684a5f6d63535dcc4156be1a97",
"type": "github"
},
"original": {
"owner": "bartoszj",
"repo": "acextract",
"type": "github"
}
},
"command-line": {
"flake": false,
"locked": {
"lastModified": 1556260068,
"narHash": "sha256-3BvUfIbbSsv8AHeg+nEjGVNDbgSOf/P7l6EFo+DvE/I=",
"owner": "iHTCboy",
"repo": "CommandLine",
"rev": "b8209dc17ac1dd0f97ebfbd6a77a0633552626ca",
"type": "github"
},
"original": {
"owner": "iHTCboy",
"repo": "CommandLine",
"type": "github"
}
},
"dsc-extractor": {
"flake": false,
"locked": {
"lastModified": 1702321461,
"narHash": "sha256-bV0MesIw0lVrhNuEkfexTFhQ73EynryQskvk8egecEs=",
"owner": "keith",
"repo": "dyld-shared-cache-extractor",
"rev": "c28b25abf09d9affa96fc1bdcaa6d7aef1f64032",
"type": "github"
},
"original": {
"owner": "keith",
"repo": "dyld-shared-cache-extractor",
"type": "github"
}
},
"nixpkgs": {
"locked": {
"lastModified": 1707205916,
"narHash": "sha256-fmRJilYGlB7VCt3XsdYxrA0u8e/K84O5xYucerUY0iM=",
"owner": "NixOS",
"repo": "nixpkgs",
"rev": "8cc79aa39bbc6eaedaf286ae655b224c71e02907",
"type": "github"
},
"original": {
"id": "nixpkgs",
"type": "indirect"
}
},
"root": {
"inputs": {
"acextract": "acextract",
"command-line": "command-line",
"dsc-extractor": "dsc-extractor",
"nixpkgs": "nixpkgs",
"snap-util": "snap-util"
}
},
"snap-util": {
"flake": false,
"locked": {
"lastModified": 1647211082,
"narHash": "sha256-zQ/0Cpo6CCeKXafeERjBCQ2gv9396c7UZU+VmViQVIc=",
"owner": "ahl",
"repo": "apfs",
"rev": "2bcf604966949f618e6a6ce33ca8ae1721494e6d",
"type": "github"
},
"original": {
"owner": "ahl",
"repo": "apfs",
"type": "github"
}
}
},
"root": "root",
"version": 7
}

206
flake.nix
View File

@@ -2,98 +2,140 @@
description = "tools to understand the internals of Apples operating systems";
inputs = {
acextract = {
url = github:bartoszj/acextract;
url = "github:bartoszj/acextract";
flake = false;
};
command-line = {
url = github:iHTCboy/CommandLine;
url = "github:iHTCboy/CommandLine";
flake = false;
};
dyld-shared-cache = {
url = github:antons/dyld-shared-cache-big-sur;
flake = false;
};
snapshot-header = {
url = "https://opensource.apple.com/tarballs/xnu/xnu-6153.141.1.tar.gz";
dsc-extractor = {
url = "github:keith/dyld-shared-cache-extractor";
flake = false;
};
snap-util = {
url = github:ahl/apfs;
url = "github:ahl/apfs";
flake = false;
};
};
outputs = { self, nixpkgs, acextract, command-line, dyld-shared-cache, snapshot-header, snap-util }: {
acextract =
with import nixpkgs { system = "x86_64-darwin"; };
let xcode12 = makeSetupHook {
deps = [ (xcodeenv.composeXcodeWrapper { version = "12.2"; }) ];
} "${xcbuildHook}/nix-support/setup-hook";
in stdenv.mkDerivation {
name = "acextract-${lib.substring 0 8 self.inputs.acextract.lastModifiedDate}";
src = acextract;
nativeBuildInputs = [ xcode12 ];
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";
installPhase = ''
mkdir -p $out/bin
cp Products/Release/acextract $out/bin/
'';
dontStrip = true;
};
dyld-shared-cache =
with import nixpkgs { system = "x86_64-darwin"; };
stdenv.mkDerivation {
name = "dyld-shared-cache-util-${lib.substring 0 8 self.inputs.dyld-shared-cache.lastModifiedDate}";
src = dyld-shared-cache;
nativeBuildInputs = [ xcbuildHook ];
xcbuildFlags = [
"-scheme dyld_shared_cache_util"
"-configuration Release"
"GCC_PREPROCESSOR_DEFINITIONS=CC_DIGEST_DEPRECATION_WARNING=\\\"\\\""
];
installPhase = ''
mkdir -p $out/bin
cp Products/Release/{dsc_extractor.bundle,dyld_shared_cache_util} $out/bin/
'';
};
snap-util =
with import nixpkgs { system = "x86_64-darwin"; };
stdenv.mkDerivation {
name = "snap-util-${lib.substring 0 8 self.inputs.snap-util.lastModifiedDate}";
src = snap-util;
nativeBuildInputs = [ (xcodeenv.composeXcodeWrapper { version = "12.2"; }) ];
preBuild = "NIX_CFLAGS_COMPILE='-idirafter ${snapshot-header}/bsd'";
installPhase = ''
mkdir -p $out/bin
cp snapUtil $out/bin/.snapUtil-wrapped
cat > $out/bin/snapUtil <<- EOF
#!/bin/sh
if csrutil status | grep -Fq disabled && sysctl kern.bootargs | grep -Fq amfi_get_out_of_my_way ; then
exec -a snapUtil $out/bin/.snapUtil-wrapped "\$@"
else
echo 'snapUtil requires SIP and AMFI to be disabled:'
echo ' boot recovery system'
echo ' run csrutil disable'
echo ' run nvram boot-args=amfi_get_out_of_my_way=0x1'
exit 1
fi
EOF
chmod a+x $out/bin/snapUtil
'';
postFixup = ''
cat > snapUtil.entitlements <<- EOF
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>com.apple.developer.vfs.snapshot</key>
<true/>
</dict>
</plist>
EOF
codesign -s - --entitlement snapUtil.entitlements $out/bin/.snapUtil-wrapped
'';
};
outputs = { self, nixpkgs, acextract, command-line, dsc-extractor, snap-util }: {
packages.x86_64-darwin = let
xcode = (nixpkgs.legacyPackages.x86_64-darwin.xcodeenv.composeXcodeWrapper {
version = "15.2";
}).overrideAttrs (attrs: { __noChroot = true; });
in {
acextract =
with nixpkgs.legacyPackages.x86_64-darwin;
let xcodeHook = makeSetupHook {
name = "xcode-hook";
propagatedBuildInputs = [ xcode ];
} "${xcbuildHook}/nix-support/setup-hook";
in stdenv.mkDerivation {
name = "acextract-${lib.substring 0 8 self.inputs.acextract.lastModifiedDate}";
src = acextract;
nativeBuildInputs = [ xcodeHook ];
__noChroot = true;
preBuild = "LD=$CC";
# FIXME: want to have submodule support for Nix flakes, workaround by explicit instantiation
postUnpack = "rmdir source/CommandLine ; ln -s ${command-line} source/CommandLine";
# FIXME: fix for Swift compiler crash
patchPhase = ''
patch -p0 <<- EOF
--- acextract/CoreUI.h
+++ acextract/CoreUI.h
@@ -24,6 +24,7 @@
// SOFTWARE.
@import Foundation;
+@import CoreGraphics;
// Hierarchy:
// - CUICatalog:
--- acextract/Operation.swift 2021-10-20 10:35:39.000000000 +0200
+++ acextract/Operation.swift 2021-10-20 10:35:46.000000000 +0200
@@ -24,6 +24,7 @@
// SOFTWARE.
import Foundation
+import ImageIO
// MARK: - Protocols
protocol Operation {
@@ -152,7 +153,7 @@
throw ExtractOperationError.cannotCreatePDFDocument
}
// Create the pdf context
- let cgPage = CGPDFDocument.page(cgPDFDocument) as! CGPDFPage // swiftlint:disable:this force_cast
+ let cgPage = cgPDFDocument.page(at: 0)!
var cgPageRect = cgPage.getBoxRect(.mediaBox)
let mutableData = NSMutableData()
EOF
'';
installPhase = ''
mkdir -p $out/bin
cp Products/Release/acextract $out/bin/
'';
dontStrip = true;
};
dsc-extractor =
with nixpkgs.legacyPackages.x86_64-darwin;
stdenv.mkDerivation {
name = "dsc-extractor-${lib.substring 0 8 self.inputs.dsc-extractor.lastModifiedDate}";
src = dsc-extractor;
nativeBuildInputs = [ cmake ];
};
snap-util =
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 = [ xcode ];
preBuild = "NIX_CFLAGS_COMPILE='-idirafter ${snapshot-header}/bsd'";
installPhase = ''
mkdir -p $out/bin
cp snapUtil $out/bin/.snapUtil-wrapped
cat > $out/bin/snapUtil <<- EOF
#!/bin/sh
if csrutil status | grep -Fq disabled && sysctl kern.bootargs | grep -Fq amfi_get_out_of_my_way ; then
exec -a ./snapUtil $out/bin/.snapUtil-wrapped "\$@"
else
echo 'snapUtil requires SIP and AMFI to be disabled:'
echo ' boot recovery system'
echo ' run csrutil disable'
echo ' run nvram boot-args=amfi_get_out_of_my_way=0x1'
exit 1
fi
EOF
chmod a+x $out/bin/snapUtil
'';
__noChroot = true;
postFixup = ''
cat > snapUtil.entitlements <<- EOF
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>com.apple.developer.vfs.snapshot</key>
<true/>
<key>com.apple.private.apfs.revert-to-snapshot</key>
<true/>
</dict>
</plist>
EOF
codesign -s - --entitlement snapUtil.entitlements $out/bin/.snapUtil-wrapped
'';
};
};
};
}

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) {
@@ -69,9 +69,11 @@ document.addEventListener("DOMContentLoaded", event => {
document.getElementById("filter").addEventListener("input", event => {
update(event.target.value.length >= 3 ? event.target.value : "");
});
// select filter text on return
// select filter text and update URL on return
document.getElementById("filter").addEventListener("change", event => {
event.target.select();
if (history.pushState)
history.pushState(null, null, "#" + event.target.value);
});
// clear filter button
document.getElementById("clear").addEventListener("click", event => {
@@ -80,7 +82,12 @@ document.addEventListener("DOMContentLoaded", event => {
update("");
});
// initialize filter control
document.getElementById("clear").click();
if (location.hash.length) {
document.getElementById("filter").value = location.hash.slice(1);
document.getElementById("filter").dispatchEvent(new Event("input"));
} else {
document.getElementById("clear").click();
}
});
});
</script>

View File

@@ -1,261 +1,352 @@
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 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
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
Action extension type for quick interaction with foreign content within a host app; extension points: com.apple.services, com.apple.ui-services
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)
Aegir astronomy watch face and lock screen; /System/Library/CoreServices/AegirProxyApp.app
AGC Apple Graphics Control, management of multiple displays and display port connections; launchd service: com.apple.displaypolicyd
ALF Application-Level Firewall, launchd service: com.apple.alf (socketfilterfw)
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-Layer Firewall, launchd service: com.apple.alf (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)
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
App Nap quiescence detection for applications and corresponding self-demotion in scheduler parameters, implemented within the application by frameworks, listens for occlusion notifications from WindowServer
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
APT Adaptive Picture Timing? ProMotion; dynamic screen updates with 120Hz base frequency
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 school exam apps that lock the device
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; dictation and semantic understanding, Intent is communicated to and enacted on the client, uses TTS for 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; 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; AvatarKit.framework
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 tool: 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
Bifrost emergency satellite connectivity; /System/Library/LocationBundles/Bifrost.bundle
Biome CloudKit-synced real-time streaming and processing for donated and invoked Intents; BiomeStreams.framework, BiomeSync.framework; local processing in Poirot database (?): PoirotSQLite.framework, PoirotUDFs.framework; launchd services: com.apple.BiomeAgent, com.apple.biomesyncd
Blast Door sandboxed sanitization process for untrusted iMessage input; BlastDoor.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
Boot Policy decides by signature check which OSes can be booted; boot-time equivalent for System Policy, configurable by SEP on Apple Silicon Macs, enforced by iBoot; command line tools: bputil, kmutil (to enroll custom kernels)
Boot Policy decides by signature check which OSes can be booted, boot-time equivalent for System Policy; LocalPolicy stores user settings, configurable from 1TR, stored by SEP, enforced by iBoot; command line tools: bputil, kmutil (to enroll custom kernels)
BPR Boot Progress Register; set-only flags to track boot mode (normal, DFU, recovery), part of Keybag class key derivation within SEP, so passcode-protected keys are inaccessible in DFU and recovery
Bridge T2 ARM CPU in Intel Macs to drive Touch Bar and Boot Policy; runs bridgeOS, a derivative of watchOS; boots the platform and the Intel CPU, communication from macOS uses RemoteXPC, which uses HTTP/2 over a USB-Ethernet interface; launchd service: com.apple.multiversed, com.apple.remoted; /System/Library/MultiversePlugins; command line tool: remotectl
Bridge T2 ARM CPU in Intel Macs to drive Touch Bar and Boot Policy; runs bridgeOS, a derivative of watchOS; boots the platform and the Intel CPU, communication from macOS uses RemoteXPC; launchd service: com.apple.multiversed; /System/Library/MultiversePlugins
Brook hand washing encouragement on watch; BrookServices.framework
Bulletin Board application push notification management, aggregates local and remote push notifications; BulletinBoard.framework
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
CDM Continuous Dialog Manager; dialog with Siri; ContinuousDialogManagerService.framework, Marrs.framework;
CEC Consumer Electronics Control; remote control for HDMI-connected devices; CoreRC.framework, IOCEC.framework
Celestial media streaming used by ReplayKit for game broadcasts; Celestial.framework
Certificates validity checked using OCSP stapling, locally installed CRLs, and transparency logs; /System/Library/Security/Certificates.bundle; /var/db/crls; 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
Cloud Pairing part of Alloy, Bluetooth out-of-band pairing over iCloud for Continuity; launchd service: com.apple.cloudpaird
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
Chamois Stage Manager
CHIP Connected Home over IP; Matter; integrated into HomeKit; HomeKitMatter.framework
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 Bluetooth
Companion iPhone that is paired with Watch; communication uses Alloy over IPsec over Bluetooth
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, SMS relay, Universal Clipboard, Watch unlock, WiFi call relay and others; SMS relay works by proxying to iMessage, other services use Alloy
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
CSR Code Security/Signing Restrictions/Requirements? also called System Integrity Protection (SIP) 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
CTK Crypto Token Kit; smart card management, also for the secure element on iOS? launchd service: com.apple.ctkd; command line tool: sc_auth
CTRR Configurable Text Read-only Region; ARM CPU register to downgrade actual permissions of memory pages; used for JIT protection and by AMFI to freeze user code after checking
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 every DMA-capable co-processor and peripheral, offers sub-page protection; SART: streaming variant for high-throughput devices (like NVMe)
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
DataVaults directories with the UF_DATAVAULT special flag; read access limited under CSR
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)
DCIM Digital Camera Images; DCIMServices.framework
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
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; CoreDuet.framework, CoreKnowledge.framework, CorePrediction.framework, CascadeEngine.framework (link to Biome); launchd services: com.apple.coreduetd, 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
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
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, 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
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? ingests and aggregates Differential Privacy data for unlinkability? 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; launchd service: com.apple.icloud.fmfd (find my friends)
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
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 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
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; extension point: com.apple.fskit.fsmodule
FUD Firmware Update Daemon; /var/db/fud; 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
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
HDR High Dynamic Range; video with wide-range transfer function; HDRProcessing.framework
HeadBoard derivative of SpringBoard for tvOS home screen; /Applications/HeadBoard.app, /Applications/PineBoard.app
HLS HTTP Live Streaming
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 second boot loader stage after UEFI (macOS) or boot ROM (iOS); DFU mode is implemented here; /System/Library/CoreServices/boot.efi
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 the iTunes conglomerate or by IMAP or DAV
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
IM Instant Messaging; usually means iMessage and FaceTime, formerly also XMPP
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
IDS Identity Directory 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
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, Shortcuts, Widgets (configuration); definition 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; 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 ID; 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
iTunes old umbrella term for a conglomerate of media services: App Stores, Apple Music, Apple TV, iCloud media library, Apple Podcasts, Podcast sync, Books Store, Books sync; server: phobos.apple.com
JARVIS Just A Rather Very Intelligent Scheduler, Mesos cluster manager for Siri, iCloud, iTunes
Jellyfish Animoji
Jetsam reclaiming of purgeable memory and terminatable apps during memory pressure; see TAL
JARVIS Just A Rather Very Intelligent Scheduler, Mesos cluster manager for Siri, iCloud, AMS
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 with passcode and lockout; 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.securityd_service, 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 applications, uses Spotlight to update cached info; launchd services: com.apple.coreservices.launchservicesd, com.apple.lsd; CoreServices.framework/LaunchServices.framework; command line tools: lsappinfo, lsregister
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
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
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
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
MMCS MobileMe Chunk Storage, used by iCloud, splits blobs into chunks and stores them at Amazon/Google with convergent encryption; MMCS.framework
MLHost background machine learning service; launchd service: com.apple.mlhostd; /System/Library/MLHost; DeepThought.framework, LighthouseBackground.framework, LighthouseBitacoraFramework.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 service: com.apple.nearbyd
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, 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; launchd service: com.apple.networkserviceproxy
OAH Rosetta
NSP Network Service Proxy; per-app VPN and proxy settings, implements Private Relay; launchd service: com.apple.networkserviceproxy
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
ODR On-Demand Resources; loaded from App Store; launchd service: com.apple.appstored
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
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)
Packet Filter network traffic filtering subsystem from OpenBSD; command line tool: pfctl
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)
Pasteboard storage for cut, copy, and paste; 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
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
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
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 ID 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
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 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
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
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 and completions based on Duet forecasting and User Activity context, also marketed as Siri features; PersonalizationPortrait.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
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), Siri watch face, Widget smart stacks; consumes Duet knowledge and app-provided timelines; /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; launchd service: com.apple.relevanced
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
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
Screen Time digital wellbeing and parental controls system, uses Device Management as policy engine, self-enforced within the application by frameworks; launchd services: com.apple.ScreenTimeAgent, com.apple.dmd
Screen Time digital wellbeing and parental controls system, uses Device Management as policy engine, self-enforced within the application by frameworks; DeviceActivity.framework, ManagedSettings.framework, FamilyControls.framework; launchd services: com.apple.ScreenTimeAgent, com.apple.dmd
SDB SQL Database; CoreSDB.framework, used by iCloud communication
Search Party portion of Find My service for offline devices; devices emit public part of rotating key pair via Bluetooth LE, other devices encrypt current location with this key and send to Apple, private key shared over CloudKit
Seatbelt process sandbox by filtering system calls; /System/Library/Sandbox/Profiles, /usr/share/sandbox; profiles written in a SBPL; 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; CloudServices.framework
SEP Secure Enclave Processor; dedicated ARM core for security services, runs L4/Darbat, inline encryption to DRAM, factory-paired channels to Touch ID/Face ID hardware and Secure Element; SEP can use but not read device UID key, usage restricted to ROM code
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
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
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 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), 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)
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
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; command line tool: skywalkctl
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
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, /System/Library/RunningBoard; launchd service: com.apple.backboardd (compositor)
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
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
Stockholm Apple Pay; also Warsaw
Stark CarPlay; companion 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; /var/db/SystemPolicy; launchd service: com.apple.security.syspolicy (invoked by kernel through host special port 29); command line tool: spctl
TAL Transparent App Lifecycle; app process is 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
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; 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/SystemPolicy; 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
Tourist backend for user-visible tips and hints; launchd service: com.apple.touristd
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?)
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, based on CONIKS, devices audit IDS records against transparency logs, log 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; uses CloudKit, codename Bladerunner; 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)
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
USD Universal Scene Description; storage format for 3D assets; /usr/lib/usd
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), Siri Shortcuts, Quick Note (context awareness), Proactive; 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
Viceroy video conferencing used by FaceTime and ReplayKit
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 VPN key management? location aware? seen in NSP, server: waldo.apple.com
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 views, configuration uses Intents; 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; 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
xART 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
Window Manager implements Stage Manager; /System/Library/CoreServices/WindowManager.app
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
XProtect signature-based malware scanner and remediation service; /Library/Apple/System/Library/CoreServices/XProtect.bundle
1 AA Term Apple account Description
1 Term Description
2 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
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 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 ACDE Apple Connect Device External? ACDEClient.framework, old two-step verification, derived from a company-internal AppleConnect system? server: appleconnect.apple.com Apple Connect Device External? ACDEClient.framework, old two-step verification, derived from a company-internal AppleConnect system?
9 ACFS ACFS Apple Clustered File System; deprecated file system for Xsan; acfs.framework Apple Clustered File System; deprecated file system for Xsan; acfs.framework
10 Acoustic ID Acoustic ID Siri feature to recognize songs song recognition and matching with Apple catalog, playback on HomePod; /System/Library/Components/AudioDSP.component
11 Action Activation extension type for quick interaction with foreign content within a host app; extension points: com.apple.services, com.apple.ui-services 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
12 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
13 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)
14 Aegir astronomy watch face and lock screen; /System/Library/CoreServices/AegirProxyApp.app
15 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
16 ALF AHAP Application-Level Firewall, launchd service: com.apple.alf (socketfilterfw) Apple Haptic Audio Pattern; file format for simultaneous audio and haptic data; CoreHaptics.framework
17 AIR Apple Intermediate Representation; synthetic bytecode architecture target for GPU binary toolchain
18 ALF Application-Layer Firewall, launchd service: com.apple.alf (socketfilterfw)
19 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
20 ALS ALS Ambient Light Sensor, AmbientDisplay.framework Ambient Light Sensor, AmbientDisplay.framework
21 Amber Amber Swift UI; SwiftUI.framework Swift UI; SwiftUI.framework
22 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) 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
23 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
24 AMP Asynchronous Multiprocessing; performance and power-efficiency cores on Apple Silicon
25 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
26 AMX Apple Matrix Extension; ARM instruction set extension for matrix operations
27 ANE Apple Neural Engine, hardware accelerator for neural network operations; ANECompiler.framework, ANEServices.framework; launchd service: com.apple.aned
28 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
29 AOP Always On Processor, part of Apple SoCs, runs RTKit as operating system
30 AOS AOS Apple Online Services? historical name for iCloud Apple Online Services? historical name for iCloud
31 Apache built-in web server; command line tool: apachectl
32 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
33 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 ID login (DSID); credentials in apsd keychain; launchd service: com.apple.apsd; server: push.apple.com
34 App Nap App Nap quiescence detection for applications and corresponding self-demotion in scheduler parameters, implemented within the application by frameworks, 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
35 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
36 APT AppleCare Adaptive Picture Timing? ProMotion; dynamic screen updates with 120Hz base frequency extended warranty; NewDeviceOutreach.framework; launchd service: com.apple.ndoagent
37 APT Adaptive Picture Timing? ProMotion; dynamic screen updates with 120Hz base frequency; AppleDisplayTCONControl.framework
38 Ask To parental-controlled user can ask parent for exceptions; launchd service: com.apple.asktod; AskToCore.framework
39 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
40 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
41 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
42 Assessment Assessment checking of System Policy; term also used for school exam apps that lock the device checking of System Policy; term also used for AAC
43 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
44 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; dictation and semantic understanding, Intent is communicated to and enacted on the client, uses TTS for output, Snippets to embed mini UIs into responses; /System/Library/Assistant, /System/Library/Snippets, AssistantServices.framework; server: *.siri.apple.com
45 ATS ATS App Transport Security, sandbox mechanism only allowing TLS-secured connections App Transport Security, sandbox mechanism only allowing TLS-secured connections
46 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
47 ATT ATT App Tracking Transparency; apps declare user tracking on app store App Tracking Transparency; apps declare user tracking on app store
48 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?
49 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
50 Avatar Avatar Memoji; AvatarKit.framework Memoji and Animoji, including pre-rendered iMessage stickers; AvatarKit.framework
51 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 tool: avbdiagnose, avbutil
52 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
53 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
54 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
55 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
56 Bifrost emergency satellite connectivity; /System/Library/LocationBundles/Bifrost.bundle
57 Biome CloudKit-synced real-time streaming and processing for donated and invoked Intents; BiomeStreams.framework, BiomeSync.framework; local processing in Poirot database (?): PoirotSQLite.framework, PoirotUDFs.framework; launchd services: com.apple.BiomeAgent, com.apple.biomesyncd
58 Blast Door sandboxed sanitization process for untrusted iMessage input; BlastDoor.framework
59 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
60 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
61 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
62 Boot Policy Boot Policy decides by signature check which OSes can be booted; boot-time equivalent for System Policy, configurable by SEP on Apple Silicon Macs, enforced by iBoot; command line tools: bputil, kmutil (to enroll custom kernels) decides by signature check which OSes can be booted, boot-time equivalent for System Policy; LocalPolicy stores user settings, configurable from 1TR, stored by SEP, enforced by iBoot; command line tools: bputil, kmutil (to enroll custom kernels)
63 BPR BPR Boot Progress Register; set-only flags to track boot mode (normal, DFU, recovery), part of Keybag class key derivation within SEP, so passcode-protected keys are inaccessible in DFU and recovery Boot Progress Register; set-only flags to track boot mode (normal, DFU, recovery), part of Keybag class key derivation within SEP, so passcode-protected keys are inaccessible in DFU and recovery
64 Bridge Bridge T2 ARM CPU in Intel Macs to drive Touch Bar and Boot Policy; runs bridgeOS, a derivative of watchOS; boots the platform and the Intel CPU, communication from macOS uses RemoteXPC, which uses HTTP/2 over a USB-Ethernet interface; launchd service: com.apple.multiversed, com.apple.remoted; /System/Library/MultiversePlugins; command line tool: remotectl T2 ARM CPU in Intel Macs to drive Touch Bar and Boot Policy; runs bridgeOS, a derivative of watchOS; boots the platform and the Intel CPU, communication from macOS uses RemoteXPC; launchd service: com.apple.multiversed; /System/Library/MultiversePlugins
65 Brook hand washing encouragement on watch; BrookServices.framework
66 Bulletin Board Bulletin Board application push notification management, aggregates local and remote push notifications; BulletinBoard.framework application push notification management, aggregates local and remote push notifications; BulletinBoard.framework
67 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)
68 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
69 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
70 CDM Continuous Dialog Manager; dialog with Siri; ContinuousDialogManagerService.framework, Marrs.framework;
71 CEC Consumer Electronics Control; remote control for HDMI-connected devices; CoreRC.framework, IOCEC.framework
72 Celestial Celestial media streaming used by ReplayKit for game broadcasts; Celestial.framework media streaming used by ReplayKit for game broadcasts; Celestial.framework
73 Certificates Certificates validity checked using OCSP stapling, locally installed CRLs, and transparency logs; /System/Library/Security/Certificates.bundle; /var/db/crls; 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
74 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
75 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; HomeKitMatter.framework
76 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)
77 Cloud Pairing CKKS part of Alloy, Bluetooth out-of-band pairing over iCloud for Continuity; launchd service: com.apple.cloudpaird 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
78 Clarity customizable accessibility mode for simplified UI; ClarityFoundation.framework
79 Classroom school teachers can create assignments for student iPads and track progress in Schoolwork app; ClassKit.framework; launchd service: com.apple.studentd
80 Cloud Pairing part of Alloy, Bluetooth out-of-band pairing over iCloud for Continuity; launchd service: com.apple.BTServer.cloudpairing (cloudpaird)
81 CMAS CMAS Commerial Mobile Alert System, now known as Wireless Emergency Alerts (WEA) Commerial Mobile Alert System, now known as Wireless Emergency Alerts (WEA)
82 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
83 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
84 Companion Companion iPhone that is paired with Watch; communication uses Alloy over Bluetooth iPhone that is paired with Watch; communication uses Alloy over IPsec over Bluetooth
85 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
86 Continuity 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 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
87 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
88 CPML CPML CorePrediction Machine Learning; CPMLBestShim.framework CorePrediction Machine Learning; CPMLBestShim.framework
89 CRD CRD Conference Room Display; Apple TV mode Conference Room Display; Apple TV mode
90 CSR Cryptex Code Security/Signing Restrictions/Requirements? also called System Integrity Protection (SIP) 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 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)
91 CTK CSR Crypto Token Kit; smart card management, also for the secure element on iOS? launchd service: com.apple.ctkd; command line tool: sc_auth Configurable Security Restrictions; XNU subsystem that is the basis for SIP
92 CTRR CTK Configurable Text Read-only Region; ARM CPU register to downgrade actual permissions of memory pages; used for JIT protection and by AMFI to freeze user code after checking Crypto Token Kit; smart card management, also for the Secure Element on iOS? launchd service: com.apple.ctkd; command line tool: sc_auth
93 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
94 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
95 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
96 Daily Briefing Siri giving an overview of information for the day; SiriDailyBriefingInternal.framework
97 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)
98 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
99 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
100 DataVaults Data Vault directories with the UF_DATAVAULT special flag; read access limited under CSR directories with the UF_DATAVAULT special flag; CSR limits access to one application
101 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)
102 DCIM DCP Digital Camera Images; DCIMServices.framework Display Co-Processor
103 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
104 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
105 Developer Mode enables launching of self-compiled apps in iOS, rough equivalent to System Policy; command line tool: devmodectl
106 DFR DFR Dynamic Function Row?, TouchBar; /System/Library/CoreServices/ControlStrip.app; DFRFoundation.framework Dynamic Function Row?, TouchBar; /System/Library/CoreServices/ControlStrip.app; DFRFoundation.framework
107 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
108 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
109 Digital Separation safety check feature to inhibit sharing relationships; DigitalSeparation.framework
110 DMC Device Management Client; part of MDM; DMCUtilities.framework
111 DMC Disk Mount Conditioner; simulates slow IO devices; command line tool: dmc
112 DND DND Do Not Disturb Do Not Disturb
113 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
114 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
115 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; CoreDuet.framework, CoreKnowledge.framework, CorePrediction.framework, CascadeEngine.framework (link to Biome); launchd services: com.apple.coreduetd, com.apple.knowledge-agent, com.apple.ospredictiond
116 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
117 EAS EAS Exchange Active Sync; network protocol for accessing Microsoft Exchange servers Exchange Active Sync; network protocol for accessing Microsoft Exchange servers
118 Energy Impact EDR 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 Extended Dynamic Range; rendering with transfer function extending beyond sRGB white; implemented natively on XDR displays and by backlight modulation on others; HDRProcessing.framework
119 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
120 Engram Engram Messages in iCloud; devices store received iMessages in CloudKit; Engram.framework Messages in iCloud; devices store received iMessages in CloudKit; Engram.framework
121 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
122 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
123 Event Monitor Eye Relief 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 screen distance warning for handheld devices; /Applications/EyeReliefUI.app
124 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)
125 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
126 Family Circle Family Circle Family Sharing; launchd services: com.apple.familycircled, com.apple.askpermissiond Family Sharing; launchd services: com.apple.familycircled, com.apple.askpermissiond
127 FDE FDE Full Disk Encryption, FileVault; command line tool: fdesetup, sysadminctl Full Disk Encryption, FileVault; command line tool: fdesetup, sysadminctl
128 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
129 Feldspar Feldspar Apple News; Silex.framework Apple News; Silex.framework
130 FiDES FiDES Fi? Distributed Evaluation Service? ingests and aggregates Differential Privacy data for unlinkability? 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? maybe private federated learning? used for emoji, Suggestions, Dictation; /System/Library/DistributedEvaluation; DistributedEvaluation.framework; server: fides-pol.apple.com
131 Find My … File Provider location sharing by explicitly querying devices remotely or collateral beacon detection using Search Party; 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
132 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)
133 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
134 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
135 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
136 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 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
137 FUD FPR Firmware Update Daemon; /var/db/fud; launchd service: com.apple.MobileAccessoryUpdater 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
138 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; extension point: com.apple.fskit.fsmodule
139 FUD Firmware Update Daemon; /var/db/fud; launchd service: com.apple.accessoryupdaterd
140 Game Mode auto-activates when games are shown full screen, throttles background work, lowers audio and input latency; launchd service: com.apple.gamepolicyd
141 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
142 Gizmo Gizmo Apple Watch; watch settings managed by Companion; /Applications/Bridge.app, /System/Library/BridgeManifests Apple Watch; watch settings managed by Companion; /Applications/Bridge.app, /System/Library/BridgeManifests
143 Group Activities SharePlay; sharing of media content and programmatic state over FaceTime calls; GroupActivities.framework, CopresenceCore.framework; launchd service: com.apple.telephonyutilities.callservicesd
144 GroupKit groups of IDS users with shared CloudKit (PCS) access; GroupKit.framework
145 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
146 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
147 HAP HAP Home Automation Protocol; CoreHAP.framework Home Automation Protocol; CoreHAP.framework
148 HDA HDA High Definition Audio; HDAInterface.framework High Definition Audio; HDAInterface.framework
149 HDI HDI Hard Disk Image; command line tool: hdiutil Hard Disk Image; command line tool: hdiutil
HDR High Dynamic Range; video with wide-range transfer function; HDRProcessing.framework
150 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
151 HLS HLS HTTP Live Streaming HTTP Live Streaming
152 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
153 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
154 Hyperion Hyperion iCloud Photos, uses CloudKit; launchd service: com.apple.cloudphotod; command line tool: cpldiagnose iCloud Photos, uses CloudKit; launchd service: com.apple.cloudphotod
155 IAP IAP iPod Accessory Protocol; IAP.framework iPod Accessory Protocol; IAP.framework
156 iBoot iBoot second boot loader stage after UEFI (macOS) or boot ROM (iOS); 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
157 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
158 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 the iTunes conglomerate or by 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
159 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
160 IDAM IDAM Inter-Device Audio and MIDI; audio connection between devices Inter-Device Audio and MIDI; audio connection between devices
161 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 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
162 IM IDV Instant Messaging; usually means iMessage and FaceTime, formerly also XMPP Identity Verification? Touch ID and Face ID; /System/Library/AccessibilityBundles/CoreIDVUI.axbundle
163 Intent IM 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 Instant Messaging; usually means iMessage and FaceTime
164 IMG4 boot files (Mach-O binaries or configuration data) with ASN.1 signature, contains RemotePolicy certificate constraints to restrict Boot Policy evaluation
165 Intent use-case-driven interaction with 3rd-party apps from a host app; used for Siri, Maps, Shortcuts, Widgets (configuration); definition 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
166 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
167 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; 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 ID; SpeechRecognitionCore.framework, ASRBridge.framework; server: guzzoni.apple.com
168 ISP ISP Image Signal Processor; camera imaging circuit in iPhones Image Signal Processor; camera imaging circuit in iPhones
169 ITML ITML iTunes Markup Language; metdata tagging for media services; ITMLKit.framework iTunes Markup Language; metdata tagging for media services; ITMLKit.framework
170 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
171 iTunes JARVIS old umbrella term for a conglomerate of media services: App Stores, Apple Music, Apple TV, iCloud media library, Apple Podcasts, Podcast sync, Books Store, Books sync; server: phobos.apple.com Just A Rather Very Intelligent Scheduler, Mesos cluster manager for Siri, iCloud, AMS
172 JARVIS Jellyfish Just A Rather Very Intelligent Scheduler, Mesos cluster manager for Siri, iCloud, iTunes Animoji; /Applications/Jellyfish.app
173 Jellyfish Jetsam Animoji reclaiming of purgeable memory and termination of apps during memory pressure
Jetsam reclaiming of purgeable memory and terminatable apps during memory pressure; see TAL
174 JSC JSC JavaScript Core; JavaScriptCore.framework; command line tool: jsc JavaScript Core; JavaScriptCore.framework; command line tool: jsc
175 Kalamata codename for the transition from x86 to ARM-based Apple Silicon
176 Kerberos Kerberos single-sign-on mechanism; Heimdal.framework; command line tools: kinit, ktutil single-sign-on mechanism; Heimdal.framework; command line tools: kinit, ktutil
177 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)
178 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
179 Keybag Keybag storage of protection class keys for Keychain and filesystem, protected by SEP with passcode and lockout; 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.securityd_service, com.apple.secd
180 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
181 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
182 Launch Services Launch Services management for applications, 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
183 Live Files user mode filesystems, currently FAT, ExFAT, NTFS on external storage; UserFS.framework, UVFSXPCService.framework; launchd service: com.apple.filesystems.userfsd
184 Liverpool Liverpool PCS codename for CloudKit PCS codename for CloudKit
185 LKDC LKDC Local Key Distribution Center, Kerberos on client machines Local Key Distribution Center, Kerberos on client machines
186 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
187 Mac Buddy Mac Buddy historic name for Setup Assistant historic name for Setup Assistant
188 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
189 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
190 Madrid Madrid iMessage; /System/Library/Messages iMessage; /System/Library/Messages
191 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)
192 Mandrake emergency siren on Apple Watch Ultra; /Applications/Mandrake.app
193 Mangrove Mangrove transfering UI tiles over XPC; Mangrove.framework, IOSurface.framework transfering UI tiles over XPC; Mangrove.framework, IOSurface.framework
194 Marco Marco Marco.framework, something about IDS and communication (iMessage, Calls), logging? Marco.framework, something about IDS and communication (iMessage, Calls), logging?
195 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
196 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 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
197 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
198 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
199 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)
200 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
201 Mesa Mesa Touch ID; /Library/Catacomb; /var/db/bkad.db Touch ID; /Library/Catacomb; /var/db/bkad.db
202 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
203 MMCS MLHost MobileMe Chunk Storage, used by iCloud, splits blobs into chunks and stores them at Amazon/Google with convergent encryption; MMCS.framework background machine learning service; launchd service: com.apple.mlhostd; /System/Library/MLHost; DeepThought.framework, LighthouseBackground.framework, LighthouseBitacoraFramework.framework,
204 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
205 Mobile Mobile prefix for iOS prefix for iOS
206 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
207 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
208 MOC MOC Managed Object Context; Core Data object space Managed Object Context; Core Data object space
209 Mondrian Mondrian photo collage arrangement in Photos.app; Mondrian.framework photo collage arrangement in Photos.app; Mondrian.framework
210 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
211 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
212 Nano Nano prefix for watchOS prefix for watchOS
213 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 service: com.apple.nearbyd
214 Newton Newton fall detection on watchOS fall detection on watchOS
215 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
216 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, 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
217 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)
218 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
219 NSP NSP Network Service Proxy; per-app VPN and proxy settings; launchd service: com.apple.networkserviceproxy Network Service Proxy; per-app VPN and proxy settings, implements Private Relay; launchd service: com.apple.networkserviceproxy
220 OAH OAH 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
221 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
222 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
223 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; launchd service: com.apple.opendirectoryd; command line tools: dscacheutil, dscl, dsconfigad, dsconfigldap, dseditgroup, dsenableroot, dserr, dsexport, dsimport, dsmemberutil, odutil
224 OpenBSM Open Basic Security Module; deprecated security audit subsystem; /etc/security, /var/audit; launchd service: com.apple.auditd; command line tool: audit
225 Opus Opus create slide shows from photos; Slideshows.framework create slide shows from photos; Slideshows.framework
226 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
227 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
228 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
229 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)
230 Packet Filter network traffic filtering subsystem from OpenBSD; command line tool: pfctl
231 Parsec 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) 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)
232 Pasteboard Party Studio storage for cut, copy, and paste; launchd service: com.apple.pboard; command line tools: pbcopy, pbpaste Karaoke mode on tvOS, where video from a paired phone is shown with effects; /System/Library/PrivateFrameworks/PartyStudio.*
233 PCS Passkey 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 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
234 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
235 Pasteboard storage for cut, copy, and paste; type of content remembered as UTI; launchd service: com.apple.pboard; command line tools: pbcopy, pbpaste
236 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
237 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
238 PCSC PCSC Personal Computer Smart Card; PCSC.framework, uses CTK Personal Computer Smart Card; PCSC.framework, uses CTK
239 PDE PDE Print Dialog Extension; old name, not a proper Extension Print Dialog Extension; old name, not a proper Extension
240 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
241 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
242 People contacts with Apple ID accounts within Group Activities and Shared With You
243 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
244 Persona Persona separation of sub-user-identities, like when using a private and managed Apple account; PersonaKit.framework; ~/Library/Personas; /System/Library/UserManagement 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
245 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
246 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
247 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; launchd service: com.apple.pluginkit.pkd; command line tool: pluginkit
248 PMC Performance Monitoring Counters; Recount.framework; /usr/share/kpep
249 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
250 Poster iPhone lock screen; PosterBoard.framework, PosterKit.framework; /Library/Wallpaper
251 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
252 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
253 Preview Shell skeleton for on-device UI previews during development; /System/Library/CoreServices/PreviewShell.app; PreviewShellKit.framework, XOJIT.framework (code live patching)
254 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
255 Proactive Proactive umbrella term for suggestions and completions based on Duet forecasting and User Activity context, also marketed as Siri features; PersonalizationPortrait.framework umbrella term for suggestions and completions based on Duet forecasting and User Activity context, also marketed as Siri features; PersonalizationPortrait.framework
256 Provenance per-file origin tracking, extended attribute com.apple.provenance stores ID into /var/db/SystemPolicyConfiguration/ExecPolicy
257 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?
258 Quagga Quagga framework for QR and barcode decoding; Quagga.framework framework for QR and barcode decoding; Quagga.framework
259 Quick Action extension type for quick interaction with foreign content within a host app; extension points: com.apple.services, com.apple.ui-services
260 Quick Look Quick Look file preview and thumbnail generation; comand line tool: qlmanage file preview and thumbnail generation; comand line tool: qlmanage
261 RAOP RAOP Remote Audio Output Protocol, AirPlay; Bonjour service: _raop._tcp Remote Audio Output Protocol, AirPlay; Bonjour service: _raop._tcp
262 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; launchd service: com.apple.rapportd; Bonjour service: _companion-link._tcp
263 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
264 Relevance Engine Relevance Engine backend for Siri suggestions (for example of Siri Shortcuts), Siri watch face, Widget smart stacks; consumes Duet knowledge and app-provided timelines; /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; launchd service: com.apple.relevanced
265 Remote Pairing Mobile Device pairing without wired connection; RemotePairingDevice.framework; Bonjour services: _remotepairing._tcp, _remotepairing-manual-pairing._tcp
266 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
267 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
268 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
269 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
270 RTKit operating system used on Apple Silicon for firmware of co-processors
271 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
272 Safety Monitor Check In; short-term location sharing in iMessage until a destination is reached; /Applications/SafetyMonitorApp.app
273 SBPL SBPL Sandbox Profile Language; a TinyScheme-based embedded DSL for Seatbelt profiles Sandbox Profile Language; a TinyScheme-based embedded DSL for Seatbelt profiles
274 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
275 Screen Reader Screen Reader VoiceOver and Braille; /System/Library/ScreenReader; ScreenReader.framework VoiceOver and Braille; /System/Library/ScreenReader; ScreenReader.framework
276 Screen Time Screen Time digital wellbeing and parental controls system, uses Device Management as policy engine, self-enforced within the application by frameworks; launchd services: com.apple.ScreenTimeAgent, com.apple.dmd digital wellbeing and parental controls system, uses Device Management as policy engine, self-enforced within the application by frameworks; DeviceActivity.framework, ManagedSettings.framework, FamilyControls.framework; launchd services: com.apple.ScreenTimeAgent, com.apple.dmd
277 SDB SDB SQL Database; CoreSDB.framework, used by iCloud communication SQL Database; CoreSDB.framework, used by iCloud communication
278 Search Party Search Party portion of Find My service for offline devices; devices emit public part of rotating key pair via Bluetooth LE, other devices encrypt current location with this key and send to Apple, private key shared over CloudKit portion of Find My service for offline devices; devices emit public part of rotating key pair via Bluetooth LE, other devices encrypt current location with this key and send to Apple, private key shared over CloudKit
279 Seatbelt Seatbelt process sandbox by filtering system calls; /System/Library/Sandbox/Profiles, /usr/share/sandbox; profiles written in a SBPL; 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)
280 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; 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
281 SEP SEP Secure Enclave Processor; dedicated ARM core for security services, runs L4/Darbat, inline encryption to DRAM, factory-paired channels to Touch ID/Face ID hardware and Secure Element; SEP can use but not read device UID key, usage restricted to ROM code 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
282 Sequoia translation; downloadable language models can run on-device; /Applications/SequoiaTranslator.app, Translation.framework
283 Seymour Apple Fitness+; workout videos integrated with Watch sensors; SeymourCore.framework
284 SF Symbols scalable UI symbols; rendered with various color treatments; SFSymbols.framework
285 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
286 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
287 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
288 Shazam audio (especially music) recognition service; ShazamKit.framework; launchd service: com.apple.shazamd; command line tool: shazam
289 Shoebox Shoebox Passbook Passbook
290 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), 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)
291 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
292 Simulator 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 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
293 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
294 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
295 SKP Sealed Key Protection; measurement of system state (boot chain IMG4 manifests, BPR, Boot Policy data, UID key, user passcode) to derive Keybag keys
296 SKS SKS Secure Key Store; handling of keybag keys within the SEP Secure Key Store; handling of keybag keys within the SEP
297 SkyLight SkyLight WindowServer; SkyLight.framework WindowServer; SkyLight.framework
298 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; 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
299 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
300 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
301 Sock Puppet Sock Puppet Watch interaction that requires Companion device Watch interaction that requires Companion device
302 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
303 SPI SPI System Private Interface; /System/Library/PrivateFrameworks System Private Interface; /System/Library/PrivateFrameworks
304 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, /System/Library/RunningBoard; 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)
305 SPRR Shadow Permission Remap Register? feature of Apple Silicon to dynamically reintepret page permissions
306 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
307 SSO SSO Single Sign-On Single Sign-On
308 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
309 Stark Stark CarPlay CarPlay; companion 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
310 Stockholm Stockholm Apple Pay; also 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
311 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
312 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
313 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
314 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)
315 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
316 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
317 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; command line tool: systemextensionsctl; launchd services: com.apple.sysextd, com.apple.nesessionmanager, com.apple.endpointsecurity.endpointsecurityd; command line tool: eslogger
318 System Policy System Policy Gatekeeper; policy engine for application launches and kext loading; /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/SystemPolicy; launchd service: com.apple.security.syspolicy (invoked by kernel through host special port 29); command line tool: spctl
319 TAL Tailspin Transparent App Lifecycle; app process is 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 sampling of process stack traces; launchd service: com.apple.tailspind; command line tool: tailspin
320 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
321 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
322 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)
323 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
324 Time Machine Time Machine automatic backup service, command line tools: tmdiagnose, tmutil automatic backup service, command line tools: tmdiagnose, tmutil
325 Tin Can Tin Can Walkie Talkie on watchOS Walkie Talkie on watchOS; /Applications/TinCan.app
326 Tones Tones ringtones; ToneLibrary.framework ringtones; ToneLibrary.framework
327 Tourist Translocation backend for user-visible tips and hints; launchd service: com.apple.touristd 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)
328 Transparency Transparency key transparency for ESS keys? Transparency.framework; launchd service: com.apple.transparencyd; server: init-kt.apple.com key transparency for ESS keys, based on CONIKS, devices audit IDS records against transparency logs, log hashes gossiped over iMessage to detect split-view attacks; Transparency.framework; launchd service: com.apple.transparencyd; server: init-kt.apple.com
329 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
330 TTS Text To Speech, neural-network-based synthesis engine (Gryphon); command line tool: say; /System/Library/Speech, /System/Library/TTSPlugins
331 TVML TVML TV Markup Language; declarative UI language for TV apps; TVMLKit.framework TV Markup Language; declarative UI language for TV apps; TVMLKit.framework
332 Ubiquity Ubiquity iCloud Drive; uses CloudKit, codename Bladerunner; 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) 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)
333 UID unique ID key, used as root key for cryptographic subsystems, generated during manufacturing by SEP and fused into hardware, only accessible by SEP
334 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
335 User Activity USD 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 Universal Scene Description; storage format for 3D assets; /usr/lib/usd
336 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), Siri Shortcuts, Quick Note (context awareness), Proactive; UserActivity.framework; launchd service: com.apple.coreservices.useractivityd
337 User Notifications User Notifications user interface for notification center; launchd service: com.apple.usernoted user interface for notification center; launchd service: com.apple.usernoted
338 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
339 VA VA Video Acceleration; AppleGVA.framework, AppleVA.framework, AppleVPA.framework Video Acceleration; AppleGVA.framework, AppleVA.framework, AppleVPA.framework
340 Viceroy VDAF video conferencing used by FaceTime and ReplayKit Verifiable Distributed Aggregation Function; part of Differential Privacy; VDAF.framework
341 Viceroy video conferencing used by FaceTime and ReplayKit; ViceroyTrace.framework
342 Virtualisation running virtual machines on macOS; Hypervisor.framework (for basic VMs and vCPUs), Virtualization.framework (brings a robust set of device models)
343 VSDB VSDB volume status database; /var/db/volinfo.database; command line tool: vsdbutil volume status database; /var/db/volinfo.database; command line tool: vsdbutil
344 Waldo Waldo VPN key management? location aware? seen in NSP, server: waldo.apple.com selects edge servers based on approximate location, part of Private Relay, seen in NSP
345 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
346 Widgets Widgets content excerpt from apps; provided via a timeline of views, configuration uses Intents; 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; extension point: com.apple.widgetkit-extension; launchd service: com.apple.chronod (timeline management and sync)
347 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
348 xART Window Manager persistent storage for SEP, used by Mesa; /System/Volumes/xarts; launchd service: com.apple.xartstorageremoted; command line tool: xartutil implements Stage Manager; /System/Library/CoreServices/WindowManager.app
349 XCS Workflow Xcode Server; continuous integration server; command line tools: xcscontrol, xcsdiagnose 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
350 xART eXtended Anti-Replay Technology; persistent storage for SEP, used by Mesa; /System/Volumes/xarts; launchd service: com.apple.xartstorageremoted; command line tool: xartutil
351 XCS Xcode Server; continuous integration server; command line tools: xcscontrol, xcsdiagnose
352 XProtect signature-based malware scanner and remediation service; /Library/Apple/System/Library/CoreServices/XProtect.bundle