TR reader Daniel tipped us off that Microsoft has released a "platform preview" of Internet Explorer 9. The preview isn't a full-fledged browser and shouldn't be viewed as a beta release. Instead, it's a platform designed to give web developers a peek at upcoming features and web technologies, such as HTML5.
Microsoft intends to update the platform preview every eight weeks. When feedback indicates that things are up to snuff, a beta version of Internet Explorer 9 will be released. Anyone interested in running the preview will need Windows 7 or Vista. Windows XP has apparently been excluded because the preview relies on "advancements in the display driver model introduced first in Windows Vista." The preview is a 32-bit affair, but Microsoft says it should run on 64-bit versions of Windows without issue.
In addition to making the platform preview available, Microsoft has also linked a number of demos designed to take advantage of the new browser's capabilities. You can read more about the Internet Explorer 9 platform preview on Microsoft's IEBlog.