Implementations in Web browsers

This is a list of known implementations of HTML5 and related features in web browsers. (It is incomplete, feel free to fix it.)

HTML5

General

• canvas with some limitation implemented in Firefox, Opera, Safari, and Konqueror 4, with ExplorerCanvas emulated in Internet Explorer
• getElementsByClassName implemented in Firefox 3, Safari 3.1, Opera 9.5
• localStorage and sessionStorage implemented in Firefox 2, IE 8, Safari 4
• Database storageimplemented in Safari 3.1 and iPhone Safari 2.0
• Custom content handlers partially implemented in Firefox 2
• ping attribute implemented in Firefox 3 (turned off by default) - note the implementation does not reflect the latest changes in the specification
• cross-document messaging implemented in Opera 9, Safari and Firefox 3, IE 8
• Audio interface implemented in Opera 9, Konqueror 4, Safari 3.1
• video element implemented in Safari 3.1 and Firefox 3.1 alfa 2, basic implementation in experimental Opera build; with mv_embed script in every browser with Java support
• Server-sent DOM events implemented in Opera 9
• contenteditable attribute implemented by Opera, Internet Explorer, Safari and Firefox 3
• Drag & drop (partially) implemented in Internet Explorer, Safari and Firefox nightly builds.
• event DOMContentLoaded implemented in Firefox, Safari, Opera
• Web Workers partly implemented in Firefox 3.1 alfa 2
• Offline Web applications implemented in Chrome (via Gears plugin), Safari 4, iPhone Safari 2.1 and Firefox 3.1
• inline MathML implemented in Firefox, partially in Opera (xhtml5 serialization only)
• inline SVG partially implemented in Firefox, Safari, Opera (xhtml5 serialization only)

Emulation

• localStorage emulation for IE6 and IE7

• LocalStorage, Web Database and Geolocation API emulated using Gears

• Web Workers partly implemented using eval() and setTimeout()

• The outline algorithm JavaScript implementation

Web Forms 2.0

• Opera 9 fully implemented Web Forms 2.
• Firefox 2 implemented input event (there is still bug #195696)
• List of future Firefox implementation tracking bugs

Emulation

• Project webforms2 emulates a big part of WF2 in every browser
• date input element with input-type-date works in Firefox, IE6/7, Safari
• Repetition Model (dropped from the spec) - Opera 9 (native), with repetitionmodel works in Firefox, IE6/7, Safari 2.0.4
• Project [1] emulate in IE6/7 validation, date and time types, range, repetition, calculated fields, datalist, autofocus.

Web Sockets

• Chrome dev channel (4.0.238.0 or later) implemented WebSocket.
• There is work ongoing to implement this for Firefox and Safari/WebKit.
• pywebsocket implemented server side.
• jWebSocket High Speed Java WebSocket Server including JavaScript/HTML5 WebSocket Client

See also

• Comparison of layout engines (HTML 5) on Wikipedia.
• An interactive view of features and which browsers they work in
• Mike Smith's notes