The Worldwide Web Consortium has released the first test results for browsers' HTML5 conformance and it looks like Microsoft has been doing a great job supporting the latest set of web standards. Taking into account seven aspects of HTML5 specifications – "attributes", "audio", "video", "canvas", "getElementsByClassName", "foreigncontent," and "xhtml5" – the latest development milestone of Internet Explorer 9 (Platform Preview 6) managed a perfect score in no less than five categories and overall showed the best adherence to HTML5 standards of all tested browsers.

According to W3C results, the only rival to come close to IE9 is Google Chrome 7.0.517.41 Beta, with a perfect score for compliance in four categories. Next in line are Firefox 4 Beta 6 and Opera 10.60 with 100% scores for three categories, while Safari 5.0.7533.16 sits at the bottom with the lowest HTML5 compliance level of all browsers - which is ironic considering Apple has been championing the new standard as a possible replacement for Adobe Flash.

Feature IE Platform Preview 6 Chrome 7.0.517.41 beta Firefox 4 Beta 6 Opera 11.00 alpha (build 1029) Safari 5.0.2 (6533.18.5)
attributes 100% 100% 100% 100% 100%
audio 100% 100% 100% 100% 100%
canvas 89.55% 80.6% 75.32% 85.35% 86.16%
getElementsByClassName 83.33% 100% 94.12% 94.44% 88.89%
foreigncontent 100% 100% 100% 0% 10%
video 100% 92.86% 71.43% 78.57% 71.43%
xhtml5 100% 42.86% 85.71% 100% 42.86%

The tests do not yet cover other aspects of the HTML5 spec such as web workers, the file API or local storage. Nevertheless it goes to show how much Microsoft's attitude towards web standards has changed in recent months and that the company is ready to challenge IE's reputation as the thorn in the side of web developers.