Emacs (pronounced ee-max) started off in 1976 as a series of editor macros (hence its name) written by Richard Matthew Stallman for the TECO text editor on the DEC PDP-10 minicomputer. Since becoming its own program separate from TECO, it has become extremely popular and widely used for two main reasons: first, free versions of Emacs are available for nearly every computer in existence; second, it’s completely customizable. Many text editors and word processors claim to be completely customizable. Some let you reassign each key’s purpose, and they let you assign a series of operations to be performed by one or two keystrokes or menu choices.

Perhaps this series of operations can have loops of repeated statements and if statements that execute one or another group of instructions based on whether a particular condition is true. If so, the editor’s proponents claim that its macro facility features a full-fledged programming language. This is usually an exaggeration, but not with Emacs.

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