http://www.gnu.org/software/emacs/windows/ntemacs.html
Emacs is included with MacOS X. This version of emacs is not aware of X-windows, but the version that is available via Fink is X-windows aware.
There is also a version of GNU Emacs for Mac OS 8 and 9, which you can download from
http://sourceforge.net/projects/mac-emacs/ However,