TriINTERCAL is an esoteric programming language created by Louis Howell in 1991 as a more difficult version of INTERCAL. It uses ternary instead of binary, and introduces the logical BUT operation.| esolangs.org
INTERCAL, an abbreviation for Compiler Language With No Pronounceable Acronym, was created in 1972, thus probably making it the first ever esoteric programming language. (See Prehistory of Esoteric Languages for an alternate view.) Donald R. Woods and James M. Lyon invented it with the goal of creating a language with no similarities whatsoever to any existing programming languages. The language largely succeeds in this goal, apart from its use of an assignment statement. It also suffers fro...| esolangs.org
PLEASE NOTE that this article only discusses the differences with other dialects of INTERCAL: familiarity with INTERCAL or C-INTERCAL may be required to understand this article.| esolangs.org
C-INTERCAL is an INTERCAL implementation first released on 12 May 1990 by Eric S. Raymond. Although compatible with INTERCAL-72, it has extensions for things like computed COME FROM, computed ABSTAIN, Threaded INTERCAL, Backtracking INTERCAL, and a debugger and profiler. The implementation is written in and compiles programs to POSIX-compatible C. It also supports TriINTERCAL.| esolangs.org
Eric, best known for his work in the free software / open source movement, is also responsible for developing C-INTERCAL in 1990, a critical moment for esolangs, from the 70s language INTERCAL, perhaps the very first esolang| esoteric.codes