Micro Users Software Exchange, Inc., doing business as Muse Software, was an American video game developer based in Baltimore, Maryland, focusing on the development of games for the first generation of home computers. The company began with developing games for Apple II, and later expanded to the Commodore 64, Atari 8-bit family, and DOS. They are best known for creating the Wolfenstein series, having developed the first two installments: 1981's Castle Wolfenstein and its 1984 sequel, Beyond Castle Wolfenstein. The brand name lapsed and was used by id Software.
