emacs

Short definition from Wiktionary

Noun

1. 1
   Any implementation or reimplementation of Emacs.
2. 2
   plural of eMac

Proper noun

1. 1
   A particular visual or WYSIWYG text editor (first written by Richard Stallman in 1975 but since reimplemented by others in several distinct versions), distinguished by its use of control characters as editing commands, by its lack of distinct "insert" and "edit" modes, and by its featurefulness and extensibility.