I use emacs for just about everything.
You can see most of my elisp at http://www.cb1.com/~john/computing/emacs/lisp/index.html, and I have also started some sourceforge projects in elisp:
An unusual thing about my emacs is that it can be used largely handsfree, with pedals driving a navigation system I have invented (emacs-versor), and with extensions to voice input, too. And I also wrote the JoyStick / GamePad interface, all of these to make editing quicker and more efficient and more elegant… and less painful. I’m aiming towards having a ConversationalEmacs.
Indeed, the fancy input stuff is largely because of RSI.