For the uninitiated, vimperator is an emacs plugin to get Firefox working with vim keybindings and firemacs 1 is for emacs keybindings.
I'm obsessed with emacs (as should already be evident) and can't really edit text without it's key-bindings. There are others like me, and hence the firemacs plugin. It's a blessing for my tribe.
Firemacs is great, except for the one great feature that it lacks - being able to jump to links/textareas without using the mouse. I've seen Nishanth do it with ease, using Vimperator. I wanted to add this feature to Firemacs, by copying some code from Vimperator to Firemacs. I directly started looking at the code, but couldn't make head or tail of it. I got a few doubts about how Vimperator works, since I'd never used it. Nishanth asked me to simply install it and try it out.
And then we had our EUREKA! moment. Vimperator and Emacs both enabled together work seamlessly well. Two obsessed people are happy and satisfied! And hopefully many more. :D
Key-bindings are a religious thing, in the world of editors!