XEmacs is a late 1980s incurred as a splinter group of GNU Emacs both graphically -use in a console text editor that can be run on almost every Unix-like operating system and Microsoft Windows. It was originally developed under the name " Lucid Emacs " by Lucid Inc., and is available as free software under the GNU General Public License in source code.


Between 1987 and 1993 there were significant delays in bringing out new GNU Emacs versions. In the late 1980s, Richard P. Gabriel and Jamie Zawinski saw by Lucid Inc. therefore forced to bring out their own version of Emacs to support Energize, an integrated development environment for C ,. Lucid therefore hired a team to improve and extend Emacs. Their intention was that these 1991 published further development would form the basis of the version 19 of GNU Emacs. However, they did not find the time to submit their changes to the party responsible for maintenance of Emacs Free Software Foundation ( FSF). Lucid developed their own version on, while a year later the FSF version 19 of Emacs published, in which they did not take up most of the new features of Lucid Emacs.

As Lucid in 1994 ceased to exist, took over other developers the development of the program. Companies like Sun Microsystems had an interest in Lucid Emacs redistribute. Due to legal concerns regarding the continued use of the trademark Lucid it was decided to rename the program and agreed on the name XEmacs.

In the software development community is called GNU Emacs, XEmacs ( and a number of similar editors ) summarized as Emacse [n ] or short Emacs, because it's all modeled on the original TECO Emacs.

Program functions

XEmacs ' text editing mode provides functions for editing of words ( delete, move, etc.) paragraphs of text, syntax highlighting to make source code more readable and user-defined keyboard shortcut to execute user-defined macros for text editing.

The program has an extensive built-in help along with five other downloadable from the site XEmacs manuals. It supports numerous natural language processing modes and for many programming and markup languages. XEmacs can run on many operating systems, such as Unix, Linux, BSD and Mac OS X. XEmacs always supported command- line based terminals and other graphics systems in addition to the X Window System. The current version can optionally also use the more modern GTK user interface library in graphics mode. Under Mac OS X, the latest version needs X11.app, a still viewed as experimental carbon version but is already usable. For Microsoft Windows, there is a native and a Cygwin version.

Users can reconfigure almost all the functionality of the editor using the Emacs Lisp programming language. Changes to the Lispscripten requires no reboot or recompile the editor. There are numerous written in Lisp extensions, which can be installed by the user, for example, with the extensive XEmacs sumo package. XEmacs also offers a stand-alone package system to integrate easily provided by third parties Lisp packages in an existing installation.


Since the beginning of the project, the XEmacs developers sought to regular publications. Currently 2 to 3 new releases per year, which is compared to previous years appear less. In addition, they sat down, a greater openness and experimentation to the destination. So XEmacs has often new features before they hold in other Emacsen collection, such as embedded images, different fonts and color syntax highlighting. Over the years, the source code has been extensively rewritten to improve the consistency of the program and to pursue modern programming concepts for data abstraction.

XEmacs has always developed very open and transparent as opposed to GNU Emacs. So all change in the sources can be publicly tracked, initially anonymous access by CVS, later on Mercurial. Changes can be discussed publicly available mailing lists. Moreover, XEmacs provides over 500 pages of documentation to program internals.

The development of the program takes place in the three branches "stable ", " gamma" and " beta", with new features first appear in "beta", but which is potentially less stable and secure. The developers released the stable major version 20.0 on 9 February 1997 to 21.0 on 12 July 1998. Currently, version 4.21.22 of 30 January 2009, the latest stable version 5.21.29 and the last beta version. A recent gamma version does not currently exist. Since the release of XEmacs 21.4.0 the version numbers follow a scheme in which an odd second number is a development version and even second number show a stable version.

XEmacs and GNU Emacs

Multiple XEmacs major developers have published their views on the cleavage of XEmacs and GNU Emacs. One of the most important of the still existing differences of opinion is the disagreement on copyright assignments. The FSF considered copyright assignments to the FSF as necessary, to defend themselves against violations of the provisions of the GPL can while the XEmacs developers argue that the waiver of such assignments has allowed that involved several major companies in the development.

Although XEmacs was cleaved from Emacs in 1991, both programs have very similar and mostly compatible functions. This is due to the fact that the XEmacs project preserves the closest possible compatibility with the API of GNU Emacs. Thus, It provides compatibility modes in the case of advanced features, particularly in relation to the integrated LISP. On the other hand, it usually does not take long until a new feature is implemented in the other editor. So much so, that module programs like AUCTeX, gnus, org -mode and Dired can run in both editors.