15 Commits

Author SHA1 Message Date
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
4 changed files with 123 additions and 59 deletions

View File

@@ -50,12 +50,17 @@ sqlite: $(DB)
# MARK: - data extraction helpers
ACEXTRACT = $(shell nix build --no-write-lock-file .\#acextract && \
ACEXTRACT = $(shell nix build --no-write-lock-file --no-warn-dirty .\#acextract && \
readlink result && rm result)/bin/acextract
DSCEXTRACTOR = $(shell nix build --no-write-lock-file .\#dsc-extractor && \
DSCEXTRACTOR = $(shell nix build --no-write-lock-file --no-warn-dirty .\#dsc-extractor && \
readlink result && rm result)/bin/dyld-shared-cache-extractor
dyld: /System/Library/dyld/dyld_shared_cache_$(shell uname -m) /System/DriverKit/System/Library/dyld/dyld_shared_cache_$(shell uname -m)
$(DB_TARGETS)::
# evaluate helper tools to catch Nix build errors early
: $(ACEXTRACT)
: $(DSCEXTRACTOR)
dyld: /System/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_x86_64h /System/Cryptexes/OS/System/DriverKit/System/Library/dyld/dyld_shared_cache_x86_64h
if ! test -x $(DSCEXTRACTOR) ; then \
printf '\033[1mdscextractor tool unavailable\033[m\n' >&2 ; \
echo 'FAIL;' ; \
@@ -69,19 +74,19 @@ XCODE = $(lastword $(wildcard /Applications/Xcode.app /Applications/Xcode-beta.a
prefix = $$(case $(1) in \
(macOS) ;; \
(macOS-dyld) echo $(dir $(realpath $(firstword $(MAKEFILE_LIST))))/dyld ;; \
(iOS) echo $(XCODE)/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot ;; \
(tvOS) echo $(XCODE)/Contents/Developer/Platforms/AppleTVOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/tvOS.simruntime/Contents/Resources/RuntimeRoot ;; \
(watchOS) echo $(XCODE)/Contents/Developer/Platforms/WatchOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/watchOS.simruntime/Contents/Resources/RuntimeRoot ;; \
(iOS) echo $(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 $(XCODE)/Contents/Developer ; find Library Toolchains Tools usr $(1) | sed 's|^|macOS /Applications/Xcode.app/Contents/Developer/|' ; \
$(2) find /Library /System /bin /dev /private /sbin /usr ! \( -path /Library/Developer/CoreSimulator/Volumes -prune \) ! \( -path /System/Volumes/Data -prune \) $(1) 2> /dev/null | sed 's/^/macOS /' ; \
find $(XCODE)/Contents/Developer $(1) | sed 's|^$(XCODE)|macOS /Applications/Xcode.app|' ; \
test -d "$(call prefix,macOS-dyld)" && cd "$(call prefix,macOS-dyld)" && find . $(1) | sed '1d;s/^\./macOS-dyld /' ; \
cd $(call prefix,iOS) ; find . $(1) | sed '1d;s/^\./iOS /' ; \
cd $(call prefix,tvOS) ; find . $(1) | sed '1d;s/^\./tvOS /' ; \
cd $(call prefix,watchOS) ; find . $(1) | sed '1d;s/^\./watchOS /' ; \
cd "$(call prefix,iOS)" ; 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 "$$path" | sed "s/'/''/g")'
@@ -135,6 +140,17 @@ db_manifests::
test -r "$(call prefix,$$os)$$path" && plutil -convert json "$(call prefix,$$os)$$path" -o - | \
sed "/: invalid object/d;s/'/''/g;s|.*|INSERT INTO info $(call file,json('&'));\n|" ; \
done
$(call find,-type f -name 'TemplateInfo.plist') | while read -r os path ; do \
test -r "$(call prefix,$$os)$$path" && { \
echo '<dict>' ; \
PlistBuddy -c 'Print Definitions:Info.plist\:NSExtension' "$(call prefix,$$os)$$path" ; \
PlistBuddy -c 'Print Definitions:Info.plist\:EXAppExtensionAttributes' "$(call prefix,$$os)$$path" ; \
PlistBuddy -c 'Print Options:0:Units:Swift:Definitions:Info.plist\:NSExtension' "$(call prefix,$$os)$$path" ; \
PlistBuddy -c 'Print Options:0:Units:Swift:Definitions:Info.plist\:EXAppExtensionAttributes' "$(call prefix,$$os)$$path" ; \
echo '</dict>' ; \
} 2> /dev/null | plutil -convert json - -o - | \
sed "/Property List error:/d;s/'/''/g;s|.*|INSERT INTO info $(call file,json('&'));\n|" ; \
done
db_assets::
if ! test -x $(ACEXTRACT) ; then \
@@ -189,7 +205,7 @@ check_binaries: internals.tsv $(DB)
check_manifests: internals.tsv $(DB)
printf '\033[1mchecking extension points...\033[m\n' >&2
grep -o 'extension points\?: [^;]*' $< | sed 's/^[^:]*: //;s/ //g;s/([^)]*)//g' | tr , '\n' | \
sed "s/'/''/g;s|.*|SELECT count(*), '&' FROM info, json_each(plist, '$$.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.tsv $(DB)

19
flake.lock generated
View File

@@ -35,11 +35,11 @@
"dsc-extractor": {
"flake": false,
"locked": {
"lastModified": 1636949004,
"narHash": "sha256-5K0CCRx5csFS5yLCWUmkkrKO1Ny3BOwasrrM2fUWgTU=",
"lastModified": 1688099356,
"narHash": "sha256-NaPFOiPwGdwVxxZr5eRklhD41IKw8DvYoZg0kLReY5k=",
"owner": "keith",
"repo": "dyld-shared-cache-extractor",
"rev": "39b5d773495d99cdfaeab1904e47338b7257c59c",
"rev": "ac746c15a62f51e1ff32e4d101b5d8c70f2cb2fe",
"type": "github"
},
"original": {
@@ -50,16 +50,15 @@
},
"nixpkgs": {
"locked": {
"lastModified": 1650109093,
"narHash": "sha256-tqlnKrAdJktRLXTou9le0oTqrYBAFpGscV5RADdpArU=",
"lastModified": 1692494774,
"narHash": "sha256-noGVoOTyZ2Kr5OFglzKYOX48cx3hggdCPbXrYMG2FDw=",
"owner": "NixOS",
"repo": "nixpkgs",
"rev": "faad370edcb37162401be50d45526f52bb16a713",
"rev": "3476a10478587dec90acb14ec6bde0966c545cc0",
"type": "github"
},
"original": {
"id": "nixpkgs",
"ref": "nixpkgs-unstable",
"type": "indirect"
}
},
@@ -92,13 +91,13 @@
"snapshot-header": {
"flake": false,
"locked": {
"narHash": "sha256-Y/DTtpnT8JQZO5Ijr+tW0IrIOuECcJ+ZvFLCgwrFt2M=",
"narHash": "sha256-/2aR6n5CbUobwbxkrGqBOAhCZLwDdIsoIOcpALhAUF8=",
"type": "tarball",
"url": "https://opensource.apple.com/tarballs/xnu/xnu-6153.141.1.tar.gz"
"url": "https://github.com/apple/darwin-xnu/archive/refs/tags/xnu-6153.141.1.tar.gz"
},
"original": {
"type": "tarball",
"url": "https://opensource.apple.com/tarballs/xnu/xnu-6153.141.1.tar.gz"
"url": "https://github.com/apple/darwin-xnu/archive/refs/tags/xnu-6153.141.1.tar.gz"
}
}
},

View File

@@ -14,26 +14,30 @@
flake = false;
};
snapshot-header = {
url = "https://opensource.apple.com/tarballs/xnu/xnu-6153.141.1.tar.gz";
url = "https://github.com/apple/darwin-xnu/archive/refs/tags/xnu-6153.141.1.tar.gz";
flake = false;
};
snap-util = {
url = "github:ahl/apfs";
flake = false;
};
nixpkgs.url = "flake:nixpkgs/nixpkgs-unstable";
};
outputs = { self, nixpkgs, acextract, command-line, dsc-extractor, snapshot-header, snap-util }: {
packages.x86_64-darwin = {
packages.x86_64-darwin = let
xcode = (nixpkgs.legacyPackages.x86_64-darwin.xcodeenv.composeXcodeWrapper {
version = "15.0.1";
}).overrideAttrs (attrs: { __noChroot = true; });
in {
acextract =
with import nixpkgs { system = "x86_64-darwin"; };
let xcode = makeSetupHook {
deps = [ (xcodeenv.composeXcodeWrapper { version = "13.4"; }) ];
let xcodeHook = makeSetupHook {
name = "xcode-hook";
propagatedBuildInputs = [ xcode ];
} "${xcbuildHook}/nix-support/setup-hook";
in stdenv.mkDerivation {
name = "acextract-${lib.substring 0 8 self.inputs.acextract.lastModifiedDate}";
src = acextract;
nativeBuildInputs = [ xcode ];
nativeBuildInputs = [ xcodeHook ];
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";
@@ -76,6 +80,7 @@
cp Products/Release/acextract $out/bin/
'';
dontStrip = true;
__noChroot = true;
};
dsc-extractor =
with import nixpkgs { system = "x86_64-darwin"; };
@@ -89,7 +94,7 @@
stdenv.mkDerivation {
name = "snap-util-${lib.substring 0 8 self.inputs.snap-util.lastModifiedDate}";
src = snap-util;
nativeBuildInputs = [ (xcodeenv.composeXcodeWrapper { version = "13.4"; }) ];
nativeBuildInputs = [ xcode ];
preBuild = "NIX_CFLAGS_COMPILE='-idirafter ${snapshot-header}/bsd'";
installPhase = ''
mkdir -p $out/bin
@@ -123,6 +128,7 @@
EOF
codesign -s - --entitlement snapUtil.entitlements $out/bin/.snapUtil-wrapped
'';
__noChroot = true;
};
};
};

View File

@@ -5,15 +5,17 @@ AA Apple Archive, see also Apple Encrypted Archive; command line tools: aa, aea,
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
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
AHAP Apple Haptic Audio Pattern; file format for simultaneous audio and haptic data; CoreHaptics.framework
AIR Apple Intermediate Representation; synthetic bytecode architecture target for GPU binary toolchain
ALF Application-Level Firewall, launchd service: com.apple.alf (socketfilterfw)
ALF Application-Layer Firewall, 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
@@ -33,6 +35,7 @@ App Nap quiescence detection for applications and corresponding self-demotion in
App Sandbox Seatbelt-based sandbox for apps; /System/Library/Sandbox/Profiles/application.sb; enabled with com.apple.security.app-sandbox entitlement; launchd service: com.apple.secinitd
AppleCare extended warranty; NewDeviceOutreach.framework; launchd service: com.apple.ndoagent
APT Adaptive Picture Timing? ProMotion; dynamic screen updates with 120Hz base frequency; AppleDisplayTCONControl.framework
Ask To parental-controlled user can ask parent for exceptions; launchd service: com.apple.asktod; AskToCore.framework
ASL Apple System Logger, superseded by Unified Logging; /etc/asl; stored in /var/log/asl; launchd service: com.apple.syslogd; command line tool: syslog
ASR Apple Software Restore; restore entire volumes from sources like disk images (HDI, SIU), also restores based on APFS snapshots and snapshot deltas; command line tool: asr
Assertions power state management allowing applications to prevent sleeping; launchd service: com.apple.powerd; command line tools: caffeinate, pmset
@@ -44,12 +47,14 @@ ATSUI Apple Type Services for Unicode Imaging; rendering engine superseded by Co
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 and Animoji (face tracking); 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
Biome CloudKit-based datastream and sync engine; BiomeStreams.framework, BiomeSync.framework; launchd services: com.apple.BiomeAgent, com.apple.biomesyncd
Bifrost emergency satellite connectivity; /System/Library/LocationBundles/Bifrost.bundle
Biome CloudKit-synced real-time event streaming and processing; widely used, primarily Avatars/People? Siri?; BiomeStreams.framework, BiomeSync.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
@@ -62,21 +67,27 @@ Bulletin Board application push notification management, aggregates local and re
Cache Delete cleanup for various caches; /System/Library/CacheDelete; launchd service: com.apple.cache_delete (deleted)
CAML Core Animation Markup Language; XML file format for layers, shapes and animations
Carousel derivative of SpringBoard for Watch home screen, watch face, and notification center
CDM Continuous Dialog Manager; dialog with Siri; ContinuousDialogManagerService.framework, Marrs.framework;
Celestial media streaming used by ReplayKit for game broadcasts; Celestial.framework
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
CHIP Connected Home over IP; Matter; integrated into HomeKit; CHIP.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: tpctl, otctl (Octagon)
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 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
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
@@ -88,22 +99,27 @@ Data Detectors text analysis to highlight phone numbers, street addresses, and t
Data Vault directories with the UF_DATAVAULT special flag; CSR limits access to one application
DAV Distributed Authoring and Versioning; network protocol on top of HTTP for syncing calendars (CalDAV), contacts (CardDAV), and formerly also bookmarks (BookmarkDAV)
DCP Display Co-Processor
DDE Device Discovery Extension; detects devices on local network without app access to local network; DeviceDiscoveryExtension.framework, DeviceDiscoveryUICore.framework; extension point: com.apple.discovery-extension
DEP Device Enrollment Program; devices check in with Apple during Setup Assistant to query for their enrollment status, retrieve MDM server URL to fetch initial configuration profile
Developer Mode enables launching of self-compiled apps in iOS, rough equivalent to System Policy; command line tool: devmodectl
DFR Dynamic Function Row?, TouchBar; /System/Library/CoreServices/ControlStrip.app; DFRFoundation.framework
DFU Device Firmware Update; special boot mode where iOS has not booted and the system can be installed over the Lightning connection
Differential Privacy crowdsourcing without user tracking; privacy budget for management of anonymity set; used for keyboard words, emoji, Spotlight searches, Parsec deep links, HealthKit usage, Safari telemetry; /System/Library/DifferentialPrivacy; stored in /var/db/DifferentialPrivacy; launchd service: com.apple.dprivacyd
Digital Separation safety check feature to inhibit sharing relationships; DigitalSeparation.framework
DMC Device Management Client; part of MDM; DMCUtilities.framework
DMC Disk Mount Conditioner; simulates slow IO devices; command line tool: dmc
DND Do Not Disturb
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; 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
EDR Extended Dynamic Range; rendering with transfer function extending beyond sRGB white; implemented natively on XDR displays and by backlight modulation on others; HDRProcessing.framework
Energy Impact unitless metric for per-application energy consumption, machine-specific coefficients; /usr/share/pmenergy, /usr/share/kpep; launchd services: com.apple.sysmond, com.apple.thermald; command line tool: powermetrics
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
@@ -112,16 +128,19 @@ FDR Factory Data/Device Reset? ensures that no downgrades are performed? servers
Feldspar Apple News; Silex.framework
FiDES Fi? Distributed Evaluation Service? aggregates Differential Privacy data for unlinkability? maybe private federated learning? used for emoji, Suggestions, Dictation; /System/Library/DistributedEvaluation; DistributedEvaluation.framework; server: fides-pol.apple.com
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)
Find My location sharing by explicitly querying devices remotely or collateral beacon detection using Search Party; FMCore.framework, FMF.framework; launchd service: com.apple.icloud.fmfd (find my friends)
Firmlink bi-directional non-symbolic link between the read-only system volume and the data volume, additional symlinks and mountpoints in the root directory are virtually allocated; /usr/share/firmlinks, /etc/synthetic.conf
Focus restriction modes for notification presentation; Focus.framework, DoNotDisturb.framework; local settings in ~/Library/DoNotDisturb
Focus restriction modes for notification presentation; focus filters for in-app display restrictions, communicat by Intents; Focus.framework, DoNotDisturb.framework; local settings in ~/Library/DoNotDisturb
FollowUp user interaction for Secure Backup wrapping with device passcode, CoreFollowUp.framework; launchd service: com.apple.followupd
FoundationDB fundamental iCloud storage database, marketed as CloudKit, separated into containers; records, blobs, and large asset storage with MMCS, server-side continuous queries can trigger push notifications, user management by IDS, sharing between users; PCS keys used for hierarchical zone, record, and asset encryption; CloudKitDaemon.framework; launchd service: com.apple.cloudd; locally stored in ~/Library/Caches/CloudKit, ~/Library/Containers/*/Data/CloudKit; command line tool: cktool
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
@@ -130,26 +149,26 @@ HDI Hard Disk Image; command line tool: hdiutil
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 boot loader stage after boot ROM or UEFI (macOS on Intel); intermediate Low-Level Bootloader (LLB); DFU mode is implemented here; /System/Library/CoreServices/boot.efi
iCDP iCloud Data Protection, codename for a set of enhancements to iCloud privacy: device passcodes used as iCSC for Secure Backup, root keys for CKKS-enabled services only synced between devices and not stored at Apple; launchd service: com.apple.cdpd
iCloud umbrella term for a conglomerate of services, consists of FoundationDB containers with PCS views for key management, supported by CKKS; uses IDS and APNS; some services under the iCloud name are actually served by AMS, IMAP, or DAV
iCSC iCloud Security Code, credential wrapping for Secure Backup, previously used a separate code, with HSA2/iCDP uses device passcodes
IDAM Inter-Device Audio and MIDI; audio connection between devices
IDS Identity Service, also IDMS, Apple ID identity management for all of Apples online services; APNS topics for signaling and messaging, see also Alloy, ESS, FaceTime, iMessage; authentication to services with Kerberos
IDS Identity Directory Service, also IDMS, Apple 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, Widgets (configuration); extension points: com.apple.intents-service, com.apple.intents-ui-service
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; SpeechRecognitionCore.framework; server: guzzoni.apple.com
ISP Image Signal Processor; camera imaging circuit in iPhones
ITML iTunes Markup Language; metdata tagging for media services; ITMLKit.framework
ITP Intelligent Tracking Prevention, cross-site tracking defenses in Safari, statistics and user interaction classify sites, cookies are partitioned and access is restricted
JARVIS Just A Rather Very Intelligent Scheduler, Mesos cluster manager for Siri, iCloud, AMS
Jellyfish Animoji
Jellyfish Animoji; /Applications/Jellyfish.app
Jetsam reclaiming of purgeable memory and termination of apps during memory pressure
JSC JavaScript Core; JavaScriptCore.framework; command line tool: jsc
Kalamata codename for the transition from x86 to ARM-based Apple Silicon
@@ -160,6 +179,7 @@ Keybag storage of protection class keys for Keychain and filesystem, protected b
Keychain storage for credentials; launchd service: com.apple.securityd; command line tools: certtool, security, systemkeychain
KIP Kernel Integrity Protection, locking of physical memory pages to prevent changes to kernel
Launch Services management for application launches, association of UTIs to apps, uses Spotlight to update cached info; launchd services: com.apple.coreservices.launchservicesd, com.apple.lsd; CoreServices.framework/LaunchServices.framework; command line tools: lsappinfo, lsregister
Live Files user mode filesystems, currently FAT, ExFAT, NTFS on external storage; UserFS.framework, UVFSXPCService.framework; launchd service: com.apple.filesystems.userfsd
Liverpool PCS codename for CloudKit
LKDC Local Key Distribution Center, Kerberos on client machines
LSM Latent Semantic Mapping, text analysis, used for spam filtering, command line tool: lsm
@@ -168,6 +188,7 @@ MAC Policy Mandatory Access Control subsystem in XNU, based on TrustedBSD, imple
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
@@ -178,13 +199,14 @@ 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
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
Nearby Interaction proximity-based interaction between devices; proximity measured using ultra wideband or derived from other technologies; used for Universal Control; NearbyInteraction.framework, Proximity.framework; launchd service: com.apple.nearbyd
@@ -194,32 +216,42 @@ Notarization app security scan by Apple; cryptographic proof stapled to code sig
Noticeboard User Notifications for Software Update and App Store, Noticeboard.framework; launchd services: com.apple.noticeboard.state (nbstated), com.apple.noticeboard.agent (nbagent)
Notifications system notification bus, unrelated to the local/remote push notifications; launchd service: com.apple.notifyd, com.apple.kuncd (invoked by kernel through host special port 10); command line tool: notifyutil; complemented by framework-level notification system (CFNotification, NSNotification); launchd services: com.apple.distnoted.xpc.daemon, com.apple.distnoted.xpc.agent
NSP Network Service Proxy; per-app VPN and proxy settings, implements Private Relay; launchd service: com.apple.networkserviceproxy
OAH Rosetta; /usr/libexec/rosetta
OAH Rosetta; ahead-of-time compiler for Intel code on Apple Silicon, usable from Linux VMs by way of a custom binformat; /usr/libexec/rosetta
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)
Party Studio Karaoke mode on tvOS, where video from a paired phone is shown with effects; /System/Library/PrivateFrameworks/PartyStudio.*
Passkey keypair used for authentication instead of password, synced via SOS, implements WebAuthn standard; keys can be used to login on separate device via QR code and Bluetooth proximity proof; AuthenticationServices.framework
Password Breach monitoring of Keychain passwords against a breach database; round-robin matching in fixed-size batches, local match against common leaks, remote match using hash prefix; launchd service: com.apple.Safari.passwordbreachd
Pasteboard storage for cut, copy, and paste; type of content remembered as UTI; launchd service: com.apple.pboard; command line tools: pbcopy, pbpaste
PCS Protected Cloud Storage; key management for separate iCloud storage compartments (PCS calls them views), each can contain FoundationDB plus bulk data stored by MMCS; see also iCDP, CKKS, Manatee; ProtectedCloudStorage.framework; /System/Library/Preferences/ProtectedCloudStorage; command line tool: pcsstatus
PAT Private Access Tokens; blind challenge-response authentication; Apple server attests user validity to token issuer, issuer performs blind signature, websites receiving the token cannot identify user; used for Private Relay, can replace CAPTCHAs
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
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; 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
PMP Port Mapping Protocol; Apple alternative to UPnP, Bonjour service: _acp-sync._tcp
Poster iPhone lock screen; PosterBoard.framework, PosterKit.framework; /Library/Wallpaper
PowerUI battery management like smart charge and power save, learns from Duet and other data; PowerUI.framework; /var/db/PowerUI; launchd service: com.apple.PowerUIAgent
Preferences storage for user-configurable settings; launchd services: com.apple.cfprefsd.xpc.daemon, com.apple.cfprefsd.xpc.agent; stored in Library/Preferences, command line tool: defaults; interaction with Synced Defaults per /System/Library/DefaultsConfigurations
Private Relay two-hop onion routing with one entry and one exit node; Apple operates entry, third-party services operate exit nodes; QUIC for payload, ODoH for DNS, approximate IP geolocation via Waldo; authentication via Attestation, propagated to proxys using RSA blind signatures
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
@@ -235,6 +267,7 @@ Routine frequently visited locations on iOS, interacts with Duet; launchd servic
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
@@ -244,13 +277,17 @@ Search Party portion of Find My service for offline devices; devices emit public
Seatbelt process sandbox by filtering system calls; profiles written in SBPL; /System/Library/Sandbox/Profiles, /usr/share/sandbox; default file access policy asks for TCC confirmation before access to folders with user data (like Documents) is allowed; command line tool: sandbox-exec; launchd service: com.apple.sandboxd (invoked by kernel through host special port 14 for logging)
Secure Backup escrow part of CKKS; escrow key individually wrapped with passcodes of trusted devices, stored in HSM to prevent brute forcing, uses SRP so passcodes are not visible to iCloud, limited number of recovery attempts; protocol called Lakitu, uses FollowUp; launchd service: com.apple.SecureBackupDaemon (com.apple.sbd); CloudServices.framework
SEP Secure Enclave Processor; dedicated ARM core for security services, runs L4/Darbat-based sepOS, inline encryption to DRAM, manages AES keys in storage DMA engine, factory-paired channels to Touch ID/Face ID hardware, Secure Element, Neural Engine; SEP can use but not read UID and GID keys; credential verification performed by hardware lockbox with retry count enforcement
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 music recognition service; ShazamKit.framework; launchd service: com.apple.shazamd
Shazam audio (especially music) recognition service; ShazamKit.framework; launchd service: com.apple.shazamd; command line tool: shazam
Shoebox Passbook
Sidecar using iPhone/iPad as Mac accessory: camera for photos and scanning, annotations, external display over low-latency WiFi (llw interface) using avconferenced encoding; SidecarCore.framework; launchd services: com.apple.sidecar-display-agent (SidecarDisplayAgent), com.apple.sidecar-relay (SidecarRelay)
Sidecar using iPhone/iPad as Mac accessory: external camera and microphone (ContinuityCapture), camera for photos and scanning (DocumentCamera.framework), 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
@@ -275,32 +312,38 @@ Symbols debug symbols for backtraces; CoreSymbolication.framework; launchd servi
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 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
Translocation app binary copied on launch to dedicated location; initiated by Launch Services for security (prevents path traversal for apps quarantined by System Policy) or path normalization (iOS apps do not expect to be moved, but can be moved on macOS)
Transparency key transparency for ESS keys? Transparency.framework; launchd service: com.apple.transparencyd; server: init-kt.apple.com
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, command line tool: say; /System/Library/Speech; synthesizer engines: MacinTalk (historic), Polyglot (phoneme-based?), Gryphon (current, DNN-based?)
TTS Text To Speech, neural-network-based synthesis engine (Gryphon); command line tool: say; /System/Library/Speech, /System/Library/TTSPlugins
TVML TV Markup Language; declarative UI language for TV apps; TVMLKit.framework
Ubiquity iCloud Drive; codename Bladerunner, uses CloudKit; CloudDocs.framework; 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
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; ViceroyTrace.framework
Virtualisation running virtual machines on macOS; Hypervisor.framework (for basic VMs and vCPUs), Virtualization.framework (brings a robust set of device models)
VSDB volume status database; /var/db/volinfo.database; command line tool: vsdbutil
Waldo selects edge servers based on approximate location, part of Private Relay, seen in NSP
WFS WebDAV File Sharing; built-in file sharing with Apache; /etc/wfs; command line tool: wfsctl
Widgets content excerpt from apps; provided via a timeline of view hierarchies, configuration uses Intents, technically very similar to complications on watch face; extension point: com.apple.widgetkit-extension
Widgets content excerpt from apps; provided via a timeline of view hierarchies, configuration uses Intents; visible on home screen, lock screen, as live activities, as watch complications; WidgetKit.framework; 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
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
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 Term Description
5 AAC Automatic Assessment Configuration; AutomaticAssessmentConfiguration.framework; puts device in a locked mode for exam-style test applications
6 AAT Apple Advanced Typography; font format and rendering engine
7 Accounts launchd service: com.apple.accountsd; /System/Library/Accounts
8 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 Apple Clustered File System; deprecated file system for Xsan; acfs.framework
10 Acoustic ID Siri feature to recognize songs
11 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
12 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 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 Apple Graphics Control, management of multiple displays and display port connections; launchd service: com.apple.displaypolicyd
16 AHAP 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-Level Firewall, launchd service: com.apple.alf (socketfilterfw) Application-Layer Firewall, launchd service: com.apple.alf (socketfilterfw)
19 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
20 ALS Ambient Light Sensor, AmbientDisplay.framework
21 Amber Swift UI; SwiftUI.framework
35 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
36 AppleCare 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 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 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 power state management allowing applications to prevent sleeping; launchd service: com.apple.powerd; command line tools: caffeinate, pmset
47 ATT 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 discretionary access control policies for high-level services; similar to PAM; policy stored in /var/db/auth.db
50 Avatar Memoji and Animoji (face tracking); AvatarKit.framework Memoji and Animoji, including pre-rendered iMessage stickers; AvatarKit.framework
51 AVB Audio Video Bridging, low-latency audio over Ethernet; launchd service: com.apple.avbdeviced; command line tool: avbdiagnose, avbutil
52 AWD Apple Wireless Diagnostics, sends system telemetry to Apple; CoreAnalytics.framework, WirelessDiagnostics.framework; launchd services: com.apple.awdd, com.apple.analyticsd
53 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
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 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 Biome Bifrost CloudKit-based datastream and sync engine; BiomeStreams.framework, BiomeSync.framework; launchd services: com.apple.BiomeAgent, com.apple.biomesyncd emergency satellite connectivity; /System/Library/LocationBundles/Bifrost.bundle
57 Biome CloudKit-synced real-time event streaming and processing; widely used, primarily Avatars/People? Siri?; BiomeStreams.framework, BiomeSync.framework; launchd services: com.apple.BiomeAgent, com.apple.biomesyncd
58 Blast Door sandboxed sanitization process for untrusted iMessage input; BlastDoor.framework
59 BOM Bill of Materials; format to store contents of installer Packages; command line tool: lsbom
60 Bonjour mDNS; launchd service: com.apple.mDNSResponder.reloaded; command line tool: dns-sd
67 Cache Delete cleanup for various caches; /System/Library/CacheDelete; launchd service: com.apple.cache_delete (deleted)
68 CAML Core Animation Markup Language; XML file format for layers, shapes and animations
69 Carousel 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 Celestial media streaming used by ReplayKit for game broadcasts; Celestial.framework
72 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
73 CHIP Chamois Connected Home over IP; Matter; integrated into HomeKit; CHIP.framework Stage Manager
74 Circle CHIP 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: tpctl, otctl (Octagon) Connected Home over IP; Matter; integrated into HomeKit; HomeKitMatter.framework
75 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)
76 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
77 Clarity customizable accessibility mode for simplified UI; ClarityFoundation.framework
78 Classroom school teachers can create assignments for student iPads and track progress in Schoolwork app; ClassKit.framework; launchd service: com.apple.studentd
79 Cloud Pairing part of Alloy, Bluetooth out-of-band pairing over iCloud for Continuity; launchd service: com.apple.BTServer.cloudpairing (cloudpaird)
80 CMAS Commerial Mobile Alert System, now known as Wireless Emergency Alerts (WEA)
81 Commpage user-mapped kernel data, like vdso/vsyscall on Linux; mapped at 0x7fffffe00000
82 Communications Filter recipient blocking for iMessage, FaceTime, Mail; launchd service: com.apple.cmfsyncagent
83 Companion iPhone that is paired with Watch; communication uses Alloy over IPsec over Bluetooth
84 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
85 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
86 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
87 CPML CorePrediction Machine Learning; CPMLBestShim.framework
88 CRD Conference Room Display; Apple TV mode
89 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)
90 CSR Configurable Security Restrictions; XNU subsystem that is the basis for SIP
91 CTK Crypto Token Kit; smart card management, also for the Secure Element on iOS? launchd service: com.apple.ctkd; command line tool: sc_auth
92 CTS Centralized Task Scheduling; execution of DAS tasks; /System/Library/UserEventPlugins/com.apple.cts.plugin
93 CVMS Core VM Server/Service? compilation of GPU shaders; launchd service: com.apple.cvmsServ
99 Data Vault directories with the UF_DATAVAULT special flag; CSR limits access to one application
100 DAV Distributed Authoring and Versioning; network protocol on top of HTTP for syncing calendars (CalDAV), contacts (CardDAV), and formerly also bookmarks (BookmarkDAV)
101 DCP Display Co-Processor
102 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
103 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
104 Developer Mode enables launching of self-compiled apps in iOS, rough equivalent to System Policy; command line tool: devmodectl
105 DFR Dynamic Function Row?, TouchBar; /System/Library/CoreServices/ControlStrip.app; DFRFoundation.framework
106 DFU Device Firmware Update; special boot mode where iOS has not booted and the system can be installed over the Lightning connection
107 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
108 Digital Separation safety check feature to inhibit sharing relationships; DigitalSeparation.framework
109 DMC Device Management Client; part of MDM; DMCUtilities.framework
110 DMC Disk Mount Conditioner; simulates slow IO devices; command line tool: dmc
111 DND Do Not Disturb
112 DSID Destination Signaling Identifier, unique ID for IDS login on a specific device
113 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
114 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; launchd services: com.apple.coreduetd, com.apple.knowledge-agent, com.apple.ospredictiond
115 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
116 EAS Exchange Active Sync; network protocol for accessing Microsoft Exchange servers
117 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
118 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
119 Engram Messages in iCloud; devices store received iMessages in CloudKit; Engram.framework
120 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
121 ESS IDS user directory, public key distribution for iMessage and CloudKit sharing, uses Transparency; server: *.ess.apple.com; launchd service: com.apple.identityservicesd
122 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
123 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)
124 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
125 Family Circle Family Sharing; launchd services: com.apple.familycircled, com.apple.askpermissiond
128 Feldspar Apple News; Silex.framework
129 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
130 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
131 Find My … 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)
132 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
133 Focus restriction modes for notification presentation; Focus.framework, DoNotDisturb.framework; local settings in ~/Library/DoNotDisturb restriction modes for notification presentation; focus filters for in-app display restrictions, communicat by Intents; Focus.framework, DoNotDisturb.framework; local settings in ~/Library/DoNotDisturb
134 FollowUp user interaction for Secure Backup wrapping with device passcode, CoreFollowUp.framework; launchd service: com.apple.followupd
135 FoundationDB fundamental iCloud storage database, marketed as CloudKit, separated into containers; records, blobs, and large asset storage with MMCS, server-side continuous queries can trigger push notifications, user management by IDS, sharing between users; PCS keys used for hierarchical zone, record, and asset encryption; CloudKitDaemon.framework; launchd service: com.apple.cloudd; locally stored in ~/Library/Caches/CloudKit, ~/Library/Containers/*/Data/CloudKit; command line tool: cktool fundamental iCloud storage database, marketed as CloudKit, separated into containers; records, blobs, and large asset storage with MMCS, server-side continuous queries can trigger push notifications, user management by IDS, sharing between users by GroupKit; PCS keys used for hierarchical zone, record, and asset encryption; CloudKitDaemon.framework; launchd service: com.apple.cloudd; locally stored in ~/Library/Caches/CloudKit, ~/Library/Containers/*/Data/CloudKit; command line tool: cktool
136 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
137 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
138 FUD Firmware Update Daemon; /var/db/fud; launchd service: com.apple.accessoryupdaterd
139 Game Mode auto-activates when games are shown full screen, throttles background work, lowers audio and input latency; launchd service: com.apple.gamepolicyd
140 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
141 Gizmo Apple Watch; watch settings managed by Companion; /Applications/Bridge.app, /System/Library/BridgeManifests
142 Group Activities SharePlay; sharing of media content and programmatic state over FaceTime calls; GroupActivities.framework, CopresenceCore.framework; launchd service: com.apple.telephonyutilities.callservicesd
143 GroupKit groups of IDS users with shared CloudKit (PCS) access; GroupKit.framework
144 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
145 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
146 HAP Home Automation Protocol; CoreHAP.framework
149 HeadBoard derivative of SpringBoard for tvOS home screen; /Applications/HeadBoard.app, /Applications/PineBoard.app
150 HLS HTTP Live Streaming
151 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
152 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
153 Hyperion iCloud Photos, uses CloudKit; launchd service: com.apple.cloudphotod; command line tool: cpldiagnose iCloud Photos, uses CloudKit; launchd service: com.apple.cloudphotod
154 IAP iPod Accessory Protocol; IAP.framework
155 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
156 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
157 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
158 iCSC iCloud Security Code, credential wrapping for Secure Backup, previously used a separate code, with HSA2/iCDP uses device passcodes
159 IDAM Inter-Device Audio and MIDI; audio connection between devices
160 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
161 IDV Identity Verification? Touch ID and Face ID; /System/Library/AccessibilityBundles/CoreIDVUI.axbundle
162 IM Instant Messaging; usually means iMessage and FaceTime
163 IMG4 boot files (Mach-O binaries or configuration data) with ASN.1 signature, contains RemotePolicy certificate constraints to restrict Boot Policy evaluation
164 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 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
165 IOKit device driver subsystem for in-kernel and DriverKit drivers, command line tool: ioreg
166 Ironwood dictation, customized on server with selected user data (contacts, app names, music titles, HomeKit names, Siri Shortcut phrases), not tied to Apple ID; SpeechRecognitionCore.framework; server: guzzoni.apple.com
167 ISP Image Signal Processor; camera imaging circuit in iPhones
168 ITML iTunes Markup Language; metdata tagging for media services; ITMLKit.framework
169 ITP Intelligent Tracking Prevention, cross-site tracking defenses in Safari, statistics and user interaction classify sites, cookies are partitioned and access is restricted
170 JARVIS Just A Rather Very Intelligent Scheduler, Mesos cluster manager for Siri, iCloud, AMS
171 Jellyfish Animoji Animoji; /Applications/Jellyfish.app
172 Jetsam reclaiming of purgeable memory and termination of apps during memory pressure
173 JSC JavaScript Core; JavaScriptCore.framework; command line tool: jsc
174 Kalamata codename for the transition from x86 to ARM-based Apple Silicon
179 Keychain storage for credentials; launchd service: com.apple.securityd; command line tools: certtool, security, systemkeychain
180 KIP Kernel Integrity Protection, locking of physical memory pages to prevent changes to kernel
181 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
182 Live Files user mode filesystems, currently FAT, ExFAT, NTFS on external storage; UserFS.framework, UVFSXPCService.framework; launchd service: com.apple.filesystems.userfsd
183 Liverpool PCS codename for CloudKit
184 LKDC Local Key Distribution Center, Kerberos on client machines
185 LSM Latent Semantic Mapping, text analysis, used for spam filtering, command line tool: lsm
188 Machine Learning Vision.framework, Espresso.framework, Futhark.framework, PhotoAnalysis.framework; used for Live Text and Visual Lookup; launchd service: com.apple.mediaanalysisd
189 Madrid iMessage; /System/Library/Messages
190 Manatee PCS key for some CloudKit containers are synced via CKKS, so data is unreadable to Apple (credential management codenames: Plesio, Stingray, Cuttlefish)
191 Mandrake emergency siren on Apple Watch Ultra; /Applications/Mandrake.app
192 Mangrove transfering UI tiles over XPC; Mangrove.framework, IOSurface.framework
193 Marco Marco.framework, something about IDS and communication (iMessage, Calls), logging?
194 Marklar codename from the PowerPC era for the port to x86, served the transition to Intel CPUs
199 Memory Debugging uses Taskport; command line tools: heap, leaks, malloc_history, stringdups, vmmap
200 Mesa Touch ID; /Library/Catacomb; /var/db/bkad.db
201 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
202 MLHost background machine learning service; launchd service: com.apple.mlhostd; /System/Library/MLHost; DeepThought.framework, LighthouseBackground.framework, LighthouseBitacoraFramework.framework,
203 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
204 Mobile prefix for iOS
205 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
206 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
207 MOC Managed Object Context; Core Data object space
208 Mondrian photo collage arrangement in Photos.app; Mondrian.framework
209 MRT Malware Removal Tool; /Library/Apple/System/Library/CoreServices/MRT.app Malware Removal Tool; /Library/Apple/System/Library/CoreServices/MRT.app; superseded by XProtect
210 Multipeer Connectivity ad-hoc networking; Bonjour for discovery; WiFi, AWDL, Bluetooth, or Ethernet as transport; optional encryption and certificate-based authentication; MultipeerConnectivity.framework
211 Nano prefix for watchOS
212 Nearby Interaction proximity-based interaction between devices; proximity measured using ultra wideband or derived from other technologies; used for Universal Control; NearbyInteraction.framework, Proximity.framework; launchd service: com.apple.nearbyd
216 Noticeboard User Notifications for Software Update and App Store, Noticeboard.framework; launchd services: com.apple.noticeboard.state (nbstated), com.apple.noticeboard.agent (nbagent)
217 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
218 NSP Network Service Proxy; per-app VPN and proxy settings, implements Private Relay; launchd service: com.apple.networkserviceproxy
219 OAH Rosetta; /usr/libexec/rosetta Rosetta; ahead-of-time compiler for Intel code on Apple Silicon, usable from Linux VMs by way of a custom binformat; /usr/libexec/rosetta
220 ODR On-Demand Resources; loaded from App Store; launchd service: com.apple.appstored
221 Onboarding data protection splash screen shown by service-connected apps; /System/Library/OnBoardingBundles; OnBoardingKit.framework
222 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
223 OpenBSM Open Basic Security Module; deprecated security audit subsystem; /etc/security, /var/audit; launchd service: com.apple.auditd; command line tool: audit
224 Opus create slide shows from photos; Slideshows.framework
225 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
226 OTUT One-Time Unlock Token; security mechanism to allow keybag unwrapping after updates
227 PAC Pointer Authentication Codes; pointers signed in unused bits to prevent ROP attacks
228 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)
229 Packet Filter network traffic filtering subsystem from OpenBSD; command line tool: pfctl
230 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)
231 Party Studio Karaoke mode on tvOS, where video from a paired phone is shown with effects; /System/Library/PrivateFrameworks/PartyStudio.*
232 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
233 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
234 Pasteboard storage for cut, copy, and paste; type of content remembered as UTI; launchd service: com.apple.pboard; command line tools: pbcopy, pbpaste
235 PCS PAT Protected Cloud Storage; key management for separate iCloud storage compartments (PCS calls them views), each can contain FoundationDB plus bulk data stored by MMCS; see also iCDP, CKKS, Manatee; ProtectedCloudStorage.framework; /System/Library/Preferences/ProtectedCloudStorage; command line tool: pcsstatus Private Access Tokens; blind challenge-response authentication; Apple server attests user validity to token issuer, issuer performs blind signature, websites receiving the token cannot identify user; used for Private Relay, can replace CAPTCHAs
236 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
237 PCSC Personal Computer Smart Card; PCSC.framework, uses CTK
238 PDE Print Dialog Extension; old name, not a proper Extension
239 PEC/PIR Private Encrypted Compute and Private Information Retrieval; used for parental controls for media and web; CipherML.framework; launchd service: com.apple.ciphermld
240 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
241 People contacts with Apple ID accounts within Group Activities and Shared With You
242 Pepper UI elements for Watch home screen and Chat, like Quickboard (canned replies), Animoji; PepperUICore.framework
243 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
244 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
245 Piano Mover Mail Drop; bulk mail attachments transfered over PCS; not to be confused with storage for iMessage attachments, which uses a CloudKit container
246 Plugin Extensions, XPC services bundled with apps or frameworks, discovery by Launch Services; launchd service: com.apple.pluginkit.pkd; command line tool: pluginkit
247 PMP Port Mapping Protocol; Apple alternative to UPnP, Bonjour service: _acp-sync._tcp
248 Poster iPhone lock screen; PosterBoard.framework, PosterKit.framework; /Library/Wallpaper
249 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
250 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
251 Private Relay Preview Shell 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 Attestation, propagated to proxys using RSA blind signatures skeleton for on-device UI previews during development; /System/Library/CoreServices/PreviewShell.app; PreviewShellKit.framework, XOJIT.framework (code live patching)
252 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
253 Proactive umbrella term for suggestions and completions based on Duet forecasting and User Activity context, also marketed as Siri features; PersonalizationPortrait.framework
254 Provenance per-file origin tracking, extended attribute com.apple.provenance stores ID into /var/db/SystemPolicyConfiguration/ExecPolicy
255 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?
256 Quagga framework for QR and barcode decoding; Quagga.framework
257 Quick Action extension type for quick interaction with foreign content within a host app; extension points: com.apple.services, com.apple.ui-services
267 RTC Real-time Telemetry and Crash reporting; RTCReporting.framework; launchd service: com.apple.rtcreportingd
268 RTKit operating system used on Apple Silicon for firmware of co-processors
269 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
270 Safety Monitor Check In; short-term location sharing in iMessage until a destination is reached; /Applications/SafetyMonitorApp.app
271 SBPL Sandbox Profile Language; a TinyScheme-based embedded DSL for Seatbelt profiles
272 SCIP System Coprocessor Integrity Protection; like KIP, but for SEP, ISP, Motion coprocessor
273 Screen Reader VoiceOver and Braille; /System/Library/ScreenReader; ScreenReader.framework
277 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)
278 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
279 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
280 Sequoia translation; downloadable language models can run on-device; /Applications/SequoiaTranslator.app, Translation.framework
281 Seymour Apple Fitness+; workout videos integrated with Watch sensors; SeymourCore.framework
282 SF Symbols scalable UI symbols; rendered with various color treatments; SFSymbols.framework
283 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
284 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
285 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
286 Shazam music recognition service; ShazamKit.framework; launchd service: com.apple.shazamd audio (especially music) recognition service; ShazamKit.framework; launchd service: com.apple.shazamd; command line tool: shazam
287 Shoebox Passbook
288 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)
289 Signpost telemetry API to report points of interest in code; launchd service: com.apple.signpost.signpost_reporter
290 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
291 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
292 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
293 SKP Sealed Key Protection; measurement of system state (boot chain IMG4 manifests, BPR, Boot Policy data, UID key, user passcode) to derive Keybag keys
312 Symptoms network diagnostics; Symptoms.framework; /var/networkd/db/netusage.sqlite; launchd service: com.apple.symptomsd (invoked by kernel through host special port 27)
313 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
314 System Configuration SystemConfiguration.framework; launchd service: com.apple.configd; command line tool: scutil
315 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
316 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
317 Tailspin sampling of process stack traces; launchd service: com.apple.tailspind; command line tool: tailspin
318 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
319 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
320 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)
321 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
322 Time Machine automatic backup service, command line tools: tmdiagnose, tmutil
323 Tin Can Walkie Talkie on watchOS Walkie Talkie on watchOS; /Applications/TinCan.app
324 Tones ringtones; ToneLibrary.framework
325 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)
326 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
327 TSS Tatsu Signing Server; online verification for firmware signatures; server: gs.apple.com
328 TTS Text To Speech, command line tool: say; /System/Library/Speech; synthesizer engines: MacinTalk (historic), Polyglot (phoneme-based?), Gryphon (current, DNN-based?) Text To Speech, neural-network-based synthesis engine (Gryphon); command line tool: say; /System/Library/Speech, /System/Library/TTSPlugins
329 TVML TV Markup Language; declarative UI language for TV apps; TVMLKit.framework
330 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)
331 UID unique ID key, used as root key for cryptographic subsystems, generated during manufacturing by SEP and fused into hardware, only accessible by SEP
332 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
333 USD Universal Scene Description; storage format for 3D assets; /usr/lib/usd
334 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
335 User Notifications user interface for notification center; launchd service: com.apple.usernoted
336 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
337 VA Video Acceleration; AppleGVA.framework, AppleVA.framework, AppleVPA.framework
338 Viceroy video conferencing used by FaceTime and ReplayKit; ViceroyTrace.framework
339 Virtualisation running virtual machines on macOS; Hypervisor.framework (for basic VMs and vCPUs), Virtualization.framework (brings a robust set of device models)
340 VSDB volume status database; /var/db/volinfo.database; command line tool: vsdbutil
341 Waldo selects edge servers based on approximate location, part of Private Relay, seen in NSP
342 WFS WebDAV File Sharing; built-in file sharing with Apache; /etc/wfs; command line tool: wfsctl
343 Widgets content excerpt from apps; provided via a timeline of view hierarchies, configuration uses Intents, technically very similar to complications on watch face; extension point: com.apple.widgetkit-extension content excerpt from apps; provided via a timeline of view hierarchies, configuration uses Intents; visible on home screen, lock screen, as live activities, as watch complications; WidgetKit.framework; extension point: com.apple.widgetkit-extension; launchd service: com.apple.chronod (timeline management and sync)
344 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
345 Window Manager implements Stage Manager; /System/Library/CoreServices/WindowManager.app
346 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
347 xART eXtended Anti-Replay Technology; persistent storage for SEP, used by Mesa; /System/Volumes/xarts; launchd service: com.apple.xartstorageremoted; command line tool: xartutil
348 XCS Xcode Server; continuous integration server; command line tools: xcscontrol, xcsdiagnose
349 XProtect signature-based malware scanner and remediation service; /Library/Apple/System/Library/CoreServices/XProtect.bundle