From the Simon Urbanek on the R-SIG-Mac Mailing List (https://stat.ethz.ch/pipermail/r-sig-mac/2005-June/001965.html) --
Ok, I assume you have working emacs - if you don't, well, that's
another story, much longer one ;). I also assume that your have Xcode
Now copy/paste the following in Terminal:
curl -O https://stat.ethz.ch/ESS/downloads/ess/ess-5.2.8.tar.gz
tar fvxz ess-5.2.8.tar.gz
rm -f ess
ln -s ess-5.2.8 ess
Now, if you don't have an emacs config file or don't care to kill it
you can copy/paste this:
echo '(load "~/ess/lisp/ess-site")' > .emacs
If you do have one, just replace the > above with >>, but make sure
you don't have other conflicting stuff there.
That should do the magic and you have ESS at your fingertips.
I'm at the point in my dissertation where I am doing quite a bit of statistical work. The only reasonable option for Macintosh uses at the moment for this kind of work, in my opinion, is R. I've been using TextWrangler from Bare Bones for quite awhile now to do my Python development, however it doesn't have syntax highlighting or language awareness for R. Since the code for my dissertation is starting to get unwieldy, I thought it might be worth a few minutes to get emacs and ESS working. Simon's instructions worked as expected and I had a functional ESS on the next launch of emacs. This also works with Aqua Emacs without modification.
As an aside, the folks involved with the Aqua Emacs project have done a tremendous job. I've been a fan of emacs for years, however I got away from using it regularly due to the dissonance that the UI brings when working on either a Mac or on the Windows side of the world. Aqua Emacs is well enough integrated with the OS X environment, that I'm tempted to dump all my native Macintosh editors.