Microsoft says IE9 is "the world's fastest browser." Mozilla claims IE9 doesn't even qualify as modern.

As Mozilla's Firefox 4 and Internet Explorer 9 move closer to release, the browser makers are sparring over each other's HTML5 capabilities, lobbing insults and contradictory test results.

After Microsoft claimed IE9 achieves 99% compliance with HTML5, compared to Firefox's 50%, Mozilla Corp. technology "evangelist" Paul Rouget fired back with a blog post titled "Is IE9 a modern browser? NO."

HTML5 BATTLES: Microsoft guy slams "President of the United States of Google"

The HTML5 standard won't be finished until 2014, so the posturing at this point is mostly for public relations. The World Wide Web Consortium has said it's too early to draw broad conclusions from HTML5 tests, but that's exactly what browser makers are doing.

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