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Likely by the end of 2011, the W3C will issue a second last-call version and begin a second round of refinements.
In the second quarter of 2012, a new phase begins, in which "implementors" of the specification--browser makers, essentially--provide feedback. During this phase, the W3C concentrates on a suite of thousands of tests to see if implementations of HTML5 really do get the same results when interpreting a Web page's code.
The culmination of this phase is a "candidate recommendation" of the HTML5 spec and at least two "interoperable implementations"--in other words, two different browsers that produce the same results on the test cases. The implementors' feedback is scheduled for completion by the first quarter of 2014.
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WebM and HD Video
As pioneers of HTML5 video standards, Firefox also supports the WebM format so you can watch open HD quality video.
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new 3D on the Web
WebGL brings 3D graphics to Firefox, opening the door for developers to create vivid games and new kinds of visualizations and experiences for the Web.
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Web Technologies
See how Firefox 4 advances the modern web with our big chart full of check marks.