The International Obfuscated C Code Contest (abbr. IOCCC) is a programming contest for the most creatively obfuscated C code held annually since 1984 (with the exception of 1997, 1999, and 2002). There are many winning entries each year, and each entry gets a category like "Worst Abuse of the C Preprocessor" or "Most Erratic Behavior".
One notable IOCCC winner (in 1986 and 1987) is Larry Wall. His achievements in IOCCC might be or might be not related to his design of Perl.