API Notes

GENERAL	DESCRIPTION	POPULAR SITE	about:config pref
Console API
CSS Conditional Rules Module Level 3
CSS Font Loading Module Level 3
CSS Object Model (CSSOM)
CSSOM View Module
Directory Upload
DOM
DOM Level 1
DOM Level 2: Core
DOM Level 2: Events
DOM Level 2: HTML			Hulu
DOM Level 2: Style		xda-developers
DOM Level 2: Traversal and Range
DOM Level 3: Core
DOM Level 3: XPath
DOM Parsing and Serialization
execCommand
Fetch		Hulu
File API		YouTube	dom.fileHandle.enabled
HTML
HTML 5
HTML 5.1
HTML: Canvas Element		maps.google.com
HTML: Channel Messaging
HTML: History Interface
HTML: Plugins
Non-Standard
Pointer Lock
Scalable Vector Graphics (SVG) 1.1 (Second Edition)			svg.disabled
Selection API		creating a reddit comment
Selectors API Level 1
Shadow DOM
Tracking Preference Expression (DNT)			privacy.donottrackheader.enabled
URL
W3C DOM4
Web Cryptography API
WebRTC 1.0: Real-time Communication Between Browser			media.peerconnection.enabled
XMLHttpRequest

PERSISTENCE/ACTIVE CONNECTIONS	DESCRIPTION	POPULAR SITE	about:config pref
Beacon			beacon.enabled
HTML: Broadcasting
HTML: Web Sockets
HTML: Web Storage		Facebook	dom.storage.enabled
HTML: Web Workers			dom.workers.enabled
Indexed Database API			dom.indexedDB.enabled
Service Workers			dom.serviceWorkers.enabled
Web Notifications			dom.webnotifications.enabled

AUDIO/VISUAL/DRM	DESCRIPTION	POPULAR SITE	about:config pref
Encoding
Encrypted Media Extensions			media.eme.enabled
Fullscreen API		YouTube	full-screen-api.enabled
Media Capture and Streams
Media Capture from DOM Elements
Media Source Extensions		YouTube	media.mediasource.enabled
MediaStream Recording
Web Audio API			dom.webaudio.enabled
WebGL Specification			webgl.disabled
WebVTT: The Web Video Text Tracks Format			media.webvtt.enabled (old pref)

PHYSICAL ENVIRONMENT	DESCRIPTION	POPULAR SITE	about:config pref
Ambient Light Sensor API			device.sensors.enabled
Battery Status API			dom.battery.enabled
DeviceOrientation Event Specification
Gamepad			dom.gamepad.enabled
Geolocation API			geo.enabled
Geometry Interfaces Module Level 1
Proximity Events
Screen Orientation API
Vibration API			dom.vibrator.enabled

BROWSER ENVIRONMENT	DESCRIPTION	POPULAR SITE	about:config pref
High Resolution Time Level 2			dom.event.highrestimestamp.enabled
Navigation Timing
Page Visibility (Second Edition)
Performance Timeline
Performance Timeline Level 2
Resource Timing			dom.enable_resource_timing
Timing / Performance Detection
Timing Control for Script-Based Animations
UI Events Specification
User Timing Level 2