How it happened is a bit embarrassing for everyone involved: I had written a program that was meant to be clear and readable and well-commented, and someone else (Aaron Grothe) reused my program, made it obfuscated and submitted it as an entry to the IOCCC (without telling me or telling the judges; which was legal because I had placed my program in the Public Domain, but perhaps a bit dishonest); the judges decided to award a prize to the program in question, and when he was asked to explain how it worked, he referred to my own work, so the judges (after consulting me) decided to make me co-winner.