Google Chrome Frame is a free plug-in for Internet Explorer. Some advanced web apps use Google Chrome Frame to provide you with additional features and better performance.

It is actually not so fresh and around for a while, however, the stable version of the plugin is released lately and it is ready-to-use.

The plugin requires 2 steps to work:
The user with IE 6, 7 or 8 should install it
The website must add a tag to the web pages (detecting IE users and inserting the tag only for them is a good idea)
After that, any user with those IE versions will have a browser with better capabilities like support for HTML5, CSS3, better JS performance and more.

Google Chrome Frame is already used by many popular websites including DeviantArt, github or HootSuite.