I’ve been using Carbon Emacs for my coding. It’s the official Mac branch of Emacs.
Just noticed AquaMacs, which is similar but “enhanced” to make it more friendly to general Mac users.
I tried it and my head exploded, because they remapped old-fashioned keys I use constantly (control-v to mean ‘scroll down a screen’). It may be better for new users but it was not good for me. Oh, and the proportionally spaced font — very pretty, but useless to me for coding in Perl, which is what I do in Emacs all day. Disaster. And new windows popping up all over the place all the time!
On the flipside, I also discovered Emacs-On-Aqua, which is based on the old NextStep port of Emacs, so it’s Cocoa-based, not Carbon-based.
Eh, it’s OK. I think I’ll just go with a recent build of Carbon Emacs.