Emacs is a class of text editors, possessing an extensive set of features, that are popular with computer programmers and other technically-proficient computer users. The original EMACS, a set of Editor MACroS for the TECO editor, was written in 1976 by Richard Stallman, Guy Steele, and Dave Moon. --Wikipedia:Emacs
 Emacs on Macs
- OS X Tiger (10.4) already includes Emacs 188.8.131.52 (for use in Terminal.app).
- Carbon versions of the latest CVS are available from Seiji Zenitani and David Caldwell.
- A more thoroughly "OSX-ified" version of Emacs is Aquamacs