Internet Explorer 10 can seamlessly "go back in time" and render websites as if it was one of its predecessors, such as IE5, IE7, IE8, IE9. Even sites tailored specifically for IE9 will work seamlessly in IE10, even though their developers might take a while to adapt the projects.
The first Platform Preview of IE10 released at MIX11 just weeks after IE9 RTW is currently available to early adopters for testing, and Microsoft offered insight into how to easily switch from one document mode to another.
"You can force the PP into different document modes. To do this, click the Debug menu and select one of the Document Modes. You can also press Alt plus the numbers 5, 7, 8, 9 or 0 to select IE5, IE7, IE8, IE9 and IE10 document modes respectively (for example, Alt + 7 for IE7).
"You can press Ctrl + Alt + 0 at any time to reset the document mode to the page default. The current document mode is shown for the currently viewed page at the left of the status bar," stated Microsoft.
With the launch of IE10 PP1, the software giant also made available the Internet Explorer Platform Preview Guide for Developers, a great resource for devs.
"The IE PP Guide for Developers provides an early look at the developer features coming to the next version of Internet Explorer. By using the documentation and samples in this guide, web developers and designers can prepare to use these new features," Microsoft notes.
At the same time, the IE Document Compatibility documentation on MSDN was refreshed in March 2011.