Update: A 64-bit version of Emacs can now be compiled from source.

With the release of Snow Leopard, the included Emacs binary was not compiled with Carbon or Cocoa support. So, if a native OS X GUI is desired, compiling your own Emacs.app may be worthwhile. That’s the route I’ve taken. The Emacs developers are making improvements to the Cocoa version while dropping support for Carbon, and a 64-bit version should be able to compile from source. I’ll update this post as I tweak my Emacs.app on Snow Leopard.

64-bit Version

Download the the “latest” source from http://savannah.gnu.org/projects/emacs (I personally used git. Known checkouts to work: Oct 12, 2009, Oct 24, 2009):

$ git clone git://git.savannah.gnu.org/emacs.git

Run ‘./configure’:

$ cd emacs
$ ./configure --with-ns

Compile and create Emacs.app:

$ make install

Move ‘./emacs/nextstep/Emacs.app’ to ‘/Applications/’:

$ mv ./nextstep/Emacs.app /Applications/

32-bit Version

If the 64-bit version doesn’t compile, you can compile a 32-bit version by doing:

$ CC="gcc -arch i386" ./configure --with-ns

Note: There is more information about compiling a 64-bit version of Emacs.app at this blog post, this mailing list thread, and this blog post.