I've been using VIM for a while to do my development. It's a terrific text editor that has been around for quite some time. Here's the rundown of what I've got set up.

MacVim: http://code.google.com/p/macvim/

Janus: https://github.com/carlhuda/janus

I've also found a few resources to help me get better with Vim as well. Here are some of my favorites:

VimCasts: http://vimcasts.org/

VimGolf: http://vimgolf.com