C-Intercal Compiler
William Patterson's DOS port of the classic Intercal-to-C compiler coauthored by Eric S. Raymond.
Intercal "Hello, World" Program
Surprisingly readable chunk of C-Intercal-only source code written by Clemens Meier.
Intercal Resource Page
Unofficial Intercal language homepage, maintained by C-Intercal implementor Eric S. Raymond. Documentation, implementations, papers, and tools.
Muppet Lab's Intercal Resources
Features the original specification and an extensive sample source code collection. Links to several compilers and to other Intercal-related sites.
Revised Reference Manual
Compiled from the original specification and from the comments and clarifications by Howell and Raymond.