The idea of a plugin that replaces one browser’s rendering engine with another’s has been floating around for years.

Google is going to give this crazy idea a shot with Chrome Frame. The idea is that an IE6+ user gets bugged that a site requires the Chrome Frame plugin. After she installs it, web pages can request that they be rendered by Chrome’s advanced layout and Javascript engines (enabling canvas, SVG, CSS animations and lots of other HTML5 goodies).

In the short run this could be a support nightmare for Microsoft and IT departments until the plugin is stable. Supposedly Google won’t take over the network stack nor any of the browser chrome (!), so it’ll just feel a little strange. On some pages right-clicking items may bring up different menus (Google will probably want to normalize this) and, notably, a few of IE8’s fancy new context-menu features won’t be available. Javascript guru Alex Russell is on the project so I have some faith that the integration will make sense.

This is the ultimate F.U. from Google to Microsoft. “We’re chewing away at Office, Windows in general, and now we’ll decide when IE gets new features.” Of course it’s also a shot over the bow of other browsers; lag behind Chrome feature-wise at your own risk.

Will this take off? There are, of course, hordes of IE users who can’t install plugins, and some who won’t, but web developers will be pushing this hard.