Knights of the Lambda Calculus

The Knights of the Lambda Calculus is a semi-fictional organization of expert Lisp and Scheme hackers.

[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.

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.

[2] A group that evolved from, or is similar to them, called The Knights of Eastern Calculus, makes a major appearance in the anime series Serial Experiments Lain, the logo of which is a reference to Freemasonry.

At one point in the anime, Lain is seen with code displayed on her handheld device that appears to be Lisp.

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 .