Copper was a DikuMUD based MUD launched in June 1991 by Linh Ngo, who was a computer science student at the University of Colorado at Denver. The MUD was named after the machine it ran on, copper.denver.Colorado.edu. Andrew Bradford, another UCD student and friend, later joined as a co-implementor. In December 1991 the Copper I source code was released, which was used in creating the popular Merc codebase, first released in December 1992. In early 1993 Copper II was released, followed by the release of Copper III more than a year later in 1994.