For the Internet Explorer 8 Beta, we’ve added an Emulate IE7 button to the command bar. It will help you with everyday browsing and with quickly checking your site as you work on it.
If you’re having trouble on a site that you’d like to browse, try the Emulate IE7 button. This causes IE8 to use the IE7 user agent string, version vector and layout modes. Also, we’re interested in webpage problems so report them using the IE8 Beta Feedback tools.
When you’re working on your pages, the combination of the Emulate IE7 button and the Developer Toolbar opens up a few more options for you.
The starting options are:
Once you get the user agent string reporting the way you like, you can use the IE8 developer tools to force IE’s layout mode to Quirks, IE7 Standards or IE8 Standards.
Paul Cutsinger Lead Program Manager User Experience