Recursive Acronym

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What Does Recursive Acronym Mean?

A recursive acronym is an acronym where the first letter is the acronym itself. For example, GNU stands for “GNU’s Not Unix.” The acronym can be expanded to multiple copies of itself in infinity. Recursive acronyms are used in some names of software projects for a humorous effect, following the example of Richard Stallman’s GNU project.


Techopedia Explains Recursive Acronym

A recursive acronym embeds a copy of itself within the acronym. One of the best known examples is Richard Stallman’s GNU project. GNU stands for “GNU’s Not Unix.” That copy in turn contains the word GNU, so the acronym is infinitely recursive. In GNU’s case, the acronym is a play on words: GNU is not Unix in the sense that it does not have any code dating to the original Bell Labs Unix, but the behavior of GNU attempts to mimic Unix systems as closely as possible.

While Stallman popularized the use of recursive acronyms in the free and open source software communities for humorous effect, the practice was already established in the MIT Artificial Intelligence Lab, of which Stallman was a part in the 1970s and early 1980s. Two LISP Machine text editors were named EINE (EINE Is Not Emacs) and ZWEI (ZWEI was EINE Initially). The latter blends two recursive acronyms.

Other well-known recursive acronyms include:

  • WINE – WINE Is Not an Emulator
  • cURL – cURL URL Request Library
  • RPM – RPM Package Manager (formerly Red Hat Package Manager)
  • PHP – PHP Hypertext Processor

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Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.