A text editor, usually characterized by its extensibility. Often described as "the extensible, customizable, self-documenting, real-time display editor." There is an Emacs-specific SE site for specialized questions.

GNU Emacs is an extensible, customizable text editor. A large part of the Emacs code base is written in a dialect of Lisp called Emacs Lisp, and the editor can be customized and extended in this language.

Emacs provides context-sensitive editing modes with syntax coloring, is self documenting, has full Unicode support and extensions to do most anything. Die-hard Emacs users do most everything from within Emacs: write code, compile, run, debug, read/compose email, browse the web, do project planning, etc.

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