At the Professional Developers Conference (PDC) 2009 day two keynote (see my PDC coverage), Microsoft president Steven Sinofsky showed off a very, very early version of Internet Explorer (IE) 9, the next major version of Microsoft's now-venerable web browser. This was an unexpected development, given that Internet Explorer 8 (see my review) shipped earlier this year and was just included with Windows 7 (see my review), which shipped last month. But Microsoft clearly wanted to demonstrate that it would continue advancing IE at a rapid pace, meeting criticisms of the current product and--the real surprise--delivering on some unexpected functionality.

What we don't know about IE 9 is a much broader discussion than that about what we do know. It's early yet, so that's OK, but I do want to set some expectations: The very early IE 9 preview build we saw this week at PDC did not contain any hint at all about the future user interface or other functional aspects of the browser. In fact, the build used in the keynote, and the one I saw separately in a meeting, lacked any kind of user interface at all. It's just a bare window frame that's designed to let the rendering engine do its thing and show off the few bits of functionality Microsoft is now publicly committing to.