News of the latest release of Aquamacs, version 2.2, appeared this week in my echo area. Given the opportunity to procrastinate, I dropped everything and upgraded; returning to work, I noticed that the version of ESS shipped with Aquamacs 2.2 is ESS 5.8, released over a year ago. The latest ESS is 5.13, available from http://ess.r-project … ads/ess/ess-5.13.tgz; the easiest way to install is described by Simon Jackman here and elaborated below:

Unarchive ESS and navigate to the folder created; edit Makeconf to set the following:

DESTDIR=/Applications/Aquamacs.app/Contents/Resources/lisp/aquamacs/edit-modes
PREFIX=$(DESTDIR)
EMACS=/Applications/Aquamacs.app/Contents/MacOS/Aquamacs
LISPDIR=$(PREFIX)/ess-mode/lisp
INFODIR=$(PREFIX)/info
ETCDIR=$(PREFIX)/ess-mode/etc

Open Terminal.app, cd to the directory created when you extracted ESS (tip: drag the little folder icon from the top of the Finder window to copy the path). Then gmake install and the updated ESS will overwrite the old version inside the app package. Done! Hopefully this post will save someone the trouble of figuring out where ESS hides deep inside the Aquamacs.app package.

[Update (4/02/11)]: Martin Maechler was kind enough to add the above to the ESS Makeconf; for future versions of ESS, Aquamacs users should simply have to uncomment the appropriate lines in the Makeconf file.