"Masochistic Programming", "Non-Electronic Computers", "Metalanguages" and "Self-Modification" are just some of the topics.

You can learn about *W Programming Language, which has no other purpose, but to annoy the user;
SMETANA language that can only modify itself, but is probably not Turing-Complete; and a tiny programming language called Brainfuck .

I blame those pesky Canadians.

Hey, alexei_, doesn't it piss you off that self-modification is considered esoteric?