Sintran III is a real-time, multitasking, multi-user operating system used with Norsk Data minicomputers from 1974.
Unlike its predecessors Sintran I and II, it was written entirely by Norsk Data, in Nord Programming Language (Nord PL, NPL), an intermediate language for Norsk Data computers.
[1][2] Sintran was mainly a command-line interface based operating system, though there were several shells which could be installed to control the user environment more strictly, by far the most popular of which was USER-ENVIRONMENT.
One of the clever features was to be able to abbreviate commands and file names between hyphens.
For example, typing LIST-FILES would give users several prompts, including for print, paging etc.