Knights of Lambda Calculus
The Knights of Lambda Calculus is a (mostly) fictional organization of Lisp and Scheme hackers. The name is a lighthearted combination of "Lambda calculus" and "Knights Templar." Lambda calculus, a mathematical formalism developed by Alonzo Church, is the basis for much of Lisp's design. The Knights Templar were a legendary organization of wealthy and powerful Christian warriors.
The Knights of the Lambda Calculus mostly exists as an in-joke at the Massachusetts Institute of Technology, but being a secret society, it may exist and wield extraordinary power. Either way, they have a neat logo.