DikuMud is one of the original muds on the internet and one of the first muds to release its source code to the internet. Many muds have based their code on DikuMUD. DikuMud was originally developed by Katja Nyboe, Tom Madsen, Hans Henrik Staerfeldt, Michael Seifert, and Sebastian Hammer at Department of Computer Science at the University of Copenhagen. It was released in 1990.