firemacs

My buddy told me this add-on. This enables not only easy browsing but also to write email on gmail much easier. This add-on implies me that firefox can be a kind of environment, not just a web browser. One can implement whatever he wants.
https://addons.mozilla.org/firefox/4141/
Keybindings of firmacs
http://www.mew.org/~kazu/firemacs.txt