There are many emacses for MacOS. There's a conventional text-mode one, a conventional X11 one, a Carbon one, a few Cocoa ones, a Mac Classic one... Up until recently I was using Aquamacs, one of the Cocoa ones. It's mostly nice, but a bit slow and it has some weird MacOS GUI idioms (every file opens in a different window, by default, for instance). Now using Emacs.app. Also Cocoa, but far better. I heartily recommend it, if you use a mac and like Emacs.