The Compiler Language With No Pronounceable Acronym (INTERCAL) is an esoteric programming language that was created as a parody by Don Woods and James M. Lyon [ru], two Princeton University students, in 1972. It satirizes aspects of the various programming languages at the time, as well as the proliferation of proposed language constructs and notations in the 1960s.

There are two maintained implementations of INTERCAL dialects: C-INTERCAL (created in 1990), maintained by Eric S. Raymond and Alex Smith, and CLC-INTERCAL, maintained by Claudio Calvelli.

According to the original manual by the authors,

The full name of the compiler is "Compiler Language With No Pronounceable Acronym", which is, for obvious reasons, abbreviated "INTERCAL".

The original Princeton implementation used punched cards and the EBCDIC character set. To allow INTERCAL to run on computers using ASCII, substitutions for two characters had to be made: $ substituted for ¢ as the mingle operator, "represent[ing] the increasing cost of software in relation to hardware", and ? was substituted for ⊻ as the unary exclusive-or operator to "correctly express the average person's reaction on first encountering exclusive-or". In recent versions of C-INTERCAL, the older operators are supported as alternatives; INTERCAL programs may now be encoded in ASCII, Latin-1, or UTF-8.

C-INTERCAL swaps the major and minor version numbers, compared to tradition. The HISTORY file shows releases starting at version 0.3 and as of May 2020^[update] having progressed to 0.31, but containing 1.26 between 0.26 and 0.27.

CLC-INTERCAL version numbering scheme was traditional until version 0.06, when it changed to the scheme documented in the README file, which says:

* The term "version" has been replaced by "perversion" for correctness