A programming language in which program flow can go sideways. Closely related to Befunge. Tutorial, reference, sample source code, Public Domain implementation available.
Specifications, implementations, sample source code collections for several strange languages, comments on obfuscated language taxonomy and on several far-out coding practices, mail list, links to many related sites.
Programming language with two main goals: confusing everyone with an obfuscated syntax, and designing as powerful a language as possible with a tiny implementation: this compiler executable is only 1024 bytes, written in pure 68000 assembler.
An interpreter for the piet programming language. In this language the programs are pictures, build out of 18 colors and black and white - this is about the real "art of programming".