Muse Software was a software and computer game publisher and developer for the first generation of home computers. They first published for the Apple II, and later expanded to the Commodore 64, Atari, and the IBM PC.
MUSE was founded in 1978 by Ed Zaron. Silas Warner was MUSE Software's first employee. Initially publishing games, the team also sold non-game software such as Super-Text (written by Zaron), a word processor, and Appilot (written by Warner), a course-writing language. Their original market was for the Apple II and II+, with their first programs sold on cassette, and later on floppy disk. They expanded their software offerings for other 6502-based computers, such as the Commodore 64 and the Atari 800.
The company closed down in 1987. Hence Wolfenstein 3D (the father of first-person shooter games) was born, trading upon the well-respected name among older gaming enthusiasts.
Source: Wikipedia, "Muse Software", available under the CC-BY-SA License.