Hot on the heels of last month's launch of Internet Explorer 9, Microsoft today launched Internet Explorer 10 Platform Preview 1, taking the first step along the path towards the next version of the browser. The announcement came at MIX11, Microsoft's annual Web and phone developer conference.

IE Corporate Vice President Dean Hachamovitch said that the company was about three weeks into the development of Internet Explorer 10. Even at this early stage, the browser has a lot of compelling new features: rich new layout options with columns, flexible boxes and grids, and CSS gradients. Following on from the pattern of the Internet Explorer 9 Platform Previews, this new release also comes with a set of new showcases on Microsoft's IE Test Drive site, and new unit tests that cover many of the new capabilities.

The new preview program is not identical to the Internet Explorer 9 program. Microsoft is lengthening the release cycle from "every eight weeks" for version 9 to "every eight to twelve weeks" for version 10. The new preview is also restricted to Windows 7; Internet Explorer 9's previews, in contrast, ran on both Windows Vista and Windows 7.

Hachamovitch hammered home the benefits of Internet Explorer 9 and 10's extensive hardware acceleration. The on-stage demos all compared Internet Explorer to Chrome—a browser that currently has only very limited hardware acceleration. While this certainly demonstrated the value such acceleration has, the omission of Firefox 4—which does include extensive hardware acceleration—was notable. Hachamovitch claimed that only browsers that directly targeted operating system functionality would be able to get the most from the hardware, implying that Firefox 4, which uses an additional software layer to allow it to offer hardware acceleration on both Windows and Linux, would never achieve performance as good as that of Internet Explorer.

In addition to the new preview, the company has also announced new previews from its HTML5 Labs. The HTML5 Labs are used to give developers early access to those Web specifications that are undergoing regular, incompatible revisions—specifications currently too unstable to be safely incorporated into the browser proper. Prototypes for WebSockets and IndexedDB have been available since December. To these, Microsoft is adding a prototype for W3C's File API, which allows trusted Web applications limited access to the local filesystem, and will shortly be adding a prototype for W3C's Media Capture API, which allows Web applications to directly access webcams and microphones—a task that currently requires the use of plugins such as Flash or Silverlight.

As was the case with Internet Explorer 9, Microsoft refused to talk about the future too much. Specifically, the company gave few hints either as to which other features would be added in future previews (though CSS transitions and more complete CSS gradient support were promised), or when it planned to ship a final release of the browser. A release in a year's time would match up pretty well with Internet Explorer 9's development cycle, but still leaves Redmond's browser lagging far behind Firefox and Chrome.