In 1986 then video game journalist Boris Schneider undertook one of the first documented fan translation efforts. Over the course of one weekend he single-handedly cracked and translated the Commodore 64 version of Murder on the Mississippi into German by using a simple hex editor and a self-written disk editor. He then sent his translated version of the game to Activision, who gave him the means to make an official translation, which they released in Germany.
Contributed by DarkChojin