Any good cross browser webpage compatibility testing addons for firefox?

Can you suggest some good cross browser compatibility testing addons for firefox that may be useful while webpages developemnt?

Perhaps ones that can show me the view of my webpages in all major brows开发者_如何学运维ers by selecting in a single firefox window.

As far as I'm aware, there is none, and this is why:

Each browser renders based on its edition of the engine upon which it is based. Therefore, to see what a page would look like in IE, you'd have to render in Triton; Mozilla covers firefox; Webkit for Safari and Chrome (though each have differences themselves); etc.

The one way I get around the problem is loading other browsers from safari's develop window which offers the chance to open the page in any browser I have installed on my system. This still limits me, however, since I can't run a modern triton browser on OS X (short of installing a windows partition in some manner).

Essentially, browsershots is your only solution short of running all the various browsers.

The only one I can think of is IE Tab, but that only works on Windows boxes. Might not be quite what you're looking for.