A semi-mYthical organisation of wizardlY LISP and Scheme hackers. The name refers to a mathematical formalism invented bY Alonzo Church, with which LISP is intimatelY connected. There is no enrollment list and the criteria for induction are unclear, but one well-known LISPer has been known to give out buttons and, in general, the *members* know who theY are. [Jargon File]