Microsoft just announced that it started work on Internet Explorer 9 three weeks ago. Steven Sinofsky, the president of Microsoft's Windows and Windows Live division, showed an early build of IE9 during his PDC keynote today. In this presentation, Sinofsky announced that Microsoft will focus on support for new standards like HTML5 and CSS3, as well as developing a faster JavaScript rendering engine. Sinofsky candidly acknowledged that IE8 did not do well on the Acid3 test, though this early build of IE9 only scored a few points higher than IE8 (24 vs. 32).

According to Sinofsky, there is still a lot of internal discussion about how much of HTML5 to support in IE9. HTML5 is still in its draft stage. Sinofsky did not say when the company plans to release IE9.

JavaScript Performance

Today's presentation of IE9 was refreshing, as Sinofsky noted that IE8's JavaScript performance was clearly slower than that of its competitors. The current build of IE9, however, has already closed this gap significantly and the difference in performance compared to the latest builds of Chrome and Firefox were only minor. As Microsoft notes, given how fast modern JavaScript engines have become over the last year, improvements in the JavaScript engine don't influence real-world performance at this point and other browser sub-systems become the bottlenecks that impede improvements.

Hardware Acceleration and Font Smoothing

Microsoft also plans to make use of DirectX-based hardware accelerated graphics and text in IE9. In his demo, Sinofsky showed that Bing maps can render about 14 frames per second in IE8. With hardware acceleration in IE9 turned on, he got 60 frames per second. In addition, this technology will also increase font quality and readability in IE9.


Microsoft already published a number of videos with the engineers working on IE9 on Channel 9 (sorry, these are Silverlight only).