Emacs, The Programmer's Editor

Most programmers are familiar with the text editor software that falls under the banner of Emacs. Emacs is today one of the most popular family of Programmer's Editor software. Development of Emacs began at the MIT AI Lab during the 1970's. The original EMACS was a set of Editor MACroS for the TECO editor. It was written in 1976 by Richard Stallman, initially together with Guy L. Steele, Jr. It was inspired by the ideas of TECMAC and TMACS, a pair of TECO macro editors. Many versions of Emacs have appeared over the years, but two are now commonly used: GNU Emacs, started by Stallman in 1984 and maintained by him until 2008, and XEmacs, a fork of GNU Emacs started in 1991 that has remained mostly compatible with its older brother. Both use a powerful extension language, Emacs Lisp, that allows them to handle tasks ranging from writing and compiling computer programs to browsing the web. Both have also been updated to work with modern PC based computers and the popular open source OS Linux.

GNU Emacs is the most popular version of the Programmer's Editor and is under active continuous development as part of the GNU project. The GNU Emacs manual describes it as "the extensible, customizable, self-documenting, real-time display editor." GNU was developed to be a free alternative to Gosling Emacs, a proprietary offshoot that had gained popularity. The first widely distributed version of GNU Emacs was 15.34, released in 1985. Versions 2 to 12 never existed. Earlier versions of GNU Emacs had been numbered "1.x.x", but sometime after version 1.12 the decision was made to drop the "1," as it was thought the major number would never change. Version 13, the first public release, was made on March 20, 1985. Like Gosling Emacs, GNU Emacs ran on Unix, but it had more features, in particular a full-featured Lisp as extension language. As a result of these features and the fact that it was free, it soon replaced Gosling Emacs as the de facto Emacs editor on Unix.

Beginning in 1991, Lucid Emacs was developed by Jamie Zawinski and others at Lucid Inc. It was originally based on an early alpha version of GNU Emacs 19. The code bases soon diverged, and the separate development teams gave up trying to merge them back into a single program. This is one of the most famous forks of a free software program. Lucid Emacs was since been renamed XEmacs; it remains the second most popular variety of Emacs Programmer's Editor after GNU Emacs.