RSTS/E
<operating system> A multi-user, general purpose timesharing {operating system} produced by Mentec, Inc. and licensed bu Digital Equipment Corporation.
RSTS/E can be used for interactive timesharing, batch processing, indirect command file processing, program development using a variety of languages and tools, and a wide variety of special purpose applications.
Up to 127 concurrent terminal users in both local and remote locations through multi-terminal services can interact with application tasks. Without multi-terminal services, 63 users are the maximum. Tasks can share computational, storage, and input/output services provided by the RSTS/E system.
Full description (http://pyrfect.ico.olivetti.com/SPD/13-01-37.txt).
