W3C Says IE9 Is Currently the Most HTML5 Compatible Browser
GIL_Dude writes "The W3C posted results for their latest HTML5 compatibility tests and have found that, so far, IE 9 has the best overall results. 'The tests cover seven aspects of the spec: "attributes," "audio," "video," "canvas," "getElementsByClassName," "foreigncontent," and "xhtml5." The tests do not yet cover web workers, the file API, local storage, or other aspects of the spec. Not do they cover CSS or other standards that have nothing to do with HTML5 but are somehow lumped under HTML5 by the likes of Apple, Google, and Microsoft.'"
A good browser has more to do with continuous improvement than a one-time "we're compatible with the latest standards right now!" IE9 betas may be great today, but shortly after its release, it will be almost certainly be behind Chrome. Shortly after that, Firefox and Safari will pass it by.
or this: Limited to Windows 7 / Vista Service Pack 2 or higher.