Because some browsers run on many different operating systems, there can be a tendency to use a “least common denominator” approach to implementing HTML5. By using more of the underlying operating system, and taking advantage of the power of the whole PC, IE9 enables developers to do more with HTML5. Running through Windows, instead of just on Windows, makes a big difference; the web runs more like a native application. This is consistent with our approach of architecting HTML5 support in, from the ground up, rather than just grafting in some HTML5 features.
The third Platform Preview of Internet Explorer 9, available now, continues the deep work around hardware acceleration to enable the same standards-based markup to run faster. This is the latest installment of the rhythm we started in March, delivering platform preview releases approximately every eight weeks and listening to developers. You’ll see more performance, same markup, and hardware accelerated HTML5.