Chrome Frame is an add in that integrates with IE and Firefox. Firefox has a similar component, and I hear that the .NET runtime finds its way into all the other browsers.

Additional integration points include:

* Protocol Handlers ([firefoxurl](http://secunia.com/advisories/25984), [cf](http://code.google.com/p/chromium/issues/detail?id=28001))
* Plugins like [Chrome Frame](http://code.google.com/chrome/chromeframe/)

This integration greatly widens my surface area of attack. I would like to still run multiple browers, but keep them completely isolated from each other.

How can I "unmerge" (for lack of a better word) all the browsers that I've installed? I'm not limited to just Chrome here (though I'm using this as an example). 

What other integration points can browsers use? Namely Chrome, Firefox, Safari, IE, Opera?