Microsoft has recently released the RTM version of Internet Explorer 9. Today at MIX 11, the Redmond company showed Internet Explorer 10 Platform Preview 1.The build string of this platform preview is 10.0.1000.16394. Here is what the official blog says about Internet Explorer 10-
We’re about three weeks into development of IE10, and based on the progress we’ve made, we want to start engaging the development community now. At the MIX conference today, we showed the new browsing engine along with several new browser test drives that anyone on the Web can try out. You can run these at www.ietestdrive.com to see emerging standards like CSS3 Multi-column Layout (link), CSS3 Grid Layout (link) and CSS3 Flexible Box Layout (link), CSS3 Gradients (link), and ES5 Strict Mode in action. We also demonstrated additional standards support (like CSS3 Transitions (link) and CSS3 3D Transforms (link)) that will be available in subsequent platform previews of IE10, which we will update every 8-12 weeks.
You can download the Internet Explorer 10 platform preview 1 from here