A closer look at Windows 8 s browser, Internet Explorer 10

Windows 8's browser, Internet Explorer 10, leads a double life. You can run it in Metro, you can run it in the traditional Windows desktop view. Underneath, however, both use the same rendering engine. This engine has been considerably improved, in both speed and support for new Web technologies such as HTML5 and CSS3. Maybe even more significantly, IE10 isn't just the browser for Windows 8, it actually becomes the underlying engine that powers Metro style applications that use HTML5 and JavaScript. When you realize that, it becomes clear that Internet Explorer 10 is a crucial piece of the Windows 8 puzzle.

At the moment, Microsoft is only making the preview version of IE10 available for Windows 8 Release Preview, but, at release, it will be available for Windows 7, Windows 8, Windows Server 2008 R2, and Windows Server 2012. To try out Windows 8 and IE10, head to the Windows 8 Release Preview download page.

Microsoft made a big push with IE9 for more standards support, and, indeed, that browser version far outstrips what IE8 offered. This is of particular importance for Windows 8's role as a tablet operating system, even though the Metro (the touch-tablet-centric part of Windows 8) guise of IE10 will include the Adobe Flash plugin built-in, as Google Chrome does. But more and more sites are relying on HTML5 to take over that plugin's functions.

Windows 8One gauge of HTML5 readiness is the HTML5Test.com site, which reports a score based on how many HTML5 features it supports, along with bonus points for non-standard-specific extras like video codecs. Out of a possible 500, IE9 earns a score of 138, compared with 414 for Google Chrome. IE10 changes this picture considerably, with a score of 319 and 6 bonus points.

But that score isn't the whole story. Far from it. HTML5Test.com merely checks for that the feature is recognized, not whether it's correctly implemented. On the IETestdrive site, Microsoft has published dozens of proof-of-concept demos showing exactly what a lot of these HTML5 features can do. You can peruse the IEBlog to read about the tons of work the IE team has done to add bleeding-edge support to the browser. Though it's often stated that Chrome and Firefox are ahead of IE in HTML5 support, some of the test drive demos show that those browsers haven't yet implemented every capability. One example is Touch Events, which lets a webpage respond to gestures.

Atop all those underlying Web technology updates, however, there's an app interface you use to browse the Web, and the main changes here are in the Metro version of IE10. Let's look at how this clean, minimalist design, full-screen, touch-friendly new interface handles your daily browsing needs. After that, I'll look at some comparative benchmark numbers