IE9 is now the primary browser on 36.2% of Windows 7 machines, Microsoft revealed in a blog post based on statistics from Net Applications, up 2% since December. It passed IE8 back in November and has been ticking up ever since as more people make the switch to Windows 7 (IE8 is the last browser compatible with Windows XP).
Microsoft attributes the rapid growth to consumer desire for a "modern browser" experience, complete with compatibility with HTML5 apps. As an example, it cited the game Cut the Rope, which Microsoft brought to the web in January via a partnership with the makers of the game. However, there are plenty of modern browsers, as Microsoft defines them, so there must be other factors at work, and one of them is surely the fact that IE9 is the default browser on any new Windows PC.
Microsoft fully released IE9 to the public on March 14. Although it added many features to make it more competitive with other browsers such as Firefox, developers have had a shaky relationship with the browser. Since IE9's market share is so large, web designers must make sites compatible with it, but some have expressed disappointment with some of its workings.
While IE9 may rule the world of Windows 7, Google Chrome is the current king of the browser heap. Chrome 15 is the most popular browser in the world, according to StatCounter, recently passing IE8.
Microsoft is currently testing the next version of its browser, Internet Explorer 10. IE10 will be the first version of the browser to be fully compatible with the upcoming Windows 8.