Lisa Operating System
The Lisa came with a low-level operating system (OS) which managed the Lisa’s memory, files, and programs. This OS was very well designed and could have given Apple a head start in making a real OS for its Lisa successor, the Macintosh. The Lisa OS people later worked in the mid 1980s on an OS for the Macintosh called OPUS which would have saved Apple lots of headaches and money in trying to get a real OS for the Macintosh. Also see Bruce Daniels’ “The Architecture of the Lisa Personal Computer” for a great discussion of this OS. These papers give an insight into the Lisa OS’ features and its development history.