Browser rivals mock Microsoft's 'native HTML5' claims

"It could be their attempt to co-opt [the term] 'HTML5' for themselves, and there are many people and organizations that would like to do the same," said Lawson. "But I'm guessing they mean hardware-accelerated HTML5."

If the second is what Microsoft means, it's a continuation of the public relations and marketing effort to cast IE9 -- and by extension IE10 -- as the best browser for Windows 7. "Microsoft is trying to say that IE9 supports HTML5 natively fast using hardware acceleration only on the latest and greatest OS," said Lawson.

Eich of Mozilla saw it Lawson's way.

"They are talking about performance, or rather the lack of it due to the lack of hardware-accelerated graphics on Windows XP," Eich said on Bugzilla.

But others in the same thread lampooned that definition.