Knights of the Lambda Calculus

The Knights of the Lambda Calculus' recursive emblem celebrates LISP's theoretical foundation, the lambda calculus. Y in the emblem refers to the fixed-point combinator and the reappearance of the picture in itself refers to recursion.

The Knights of the Lambda Calculus is a semi-fictional organization of expert Lisp and Scheme hackers. The name refers to the lambda calculus, a mathematical formalism invented by Alonzo Church, with which Lisp is intimately connected, and references the Knights Templar.[1]

There is no actual organization that goes by the name Knights of the Lambda Calculus; it mostly only exists as a hacker culture in-joke. The concept most likely originated at MIT. For example, in the Structure and Interpretation of Computer Programs video lectures, Gerald Jay Sussman presents the audience with the button, saying they are now members of this special group. However, according to the Jargon File, a "well-known LISPer" has been known to give out buttons with Knights insignia on them, and some people have claimed to have membership in the Knights.[2]

  1. ^ This article is based on material taken from Knights+of+the+Lambda+Calculus at the Free On-line Dictionary of Computing prior to 1 November 2008 and incorporated under the "relicensing" terms of the GFDL, version 1.3 or later.
  2. ^ Raymond, Eric. "Knights of the Lambda Calculus". The Jargon File. Retrieved 2015-04-01.