Vimperator is a Firefox browser extension with strong inspiration from the Vim text editor, with a mind towards faster and more efficient browsing. It has similar key bindings and you could call it a modal web browser, as key bindings differ according to which mode you are in. For example, it has a special Hint mode, where you can follow links easily with the keyboard only. Also most functionality is available as commands, typing :back
will go back within the current page history, just like hitting the back button in the toolbar.
But vimperator is more than just a simple command interface to firefox — it is a complete development environment as well. If you are a web developer, you can enjoy an interactive JavaScript shell — even with completion support.
Have a look, xmonad and vimperator and no more mouse is needed to work :)