For quite some time I was looking for a solution to embed the Gecko engine (which is used in Firefox to render the HTML pages) into Emacs buffers, more or less like it is possible with the w3m mode. But of course the latter is only text mode while Gecko would be graphics and therefore (maybe) more complicated. Anyway, somebody now did something in the other direction: an chrome implementation of an Emacs like user interface for Firefox Look here. It’s called Conkeror (no idea why. Konqueror is the KDE browser which existed long before this project was started) and replaces the Firefox GUI:

Now it only has to work on my machine. Not that I want to use it so eagerly, but it looks cool It is the same guy btw. who wrote ratpoison, a minimalistic Emacs like or GNU screen like window manager for X-Windows.