operating system
operating system:: [techspeak] n. (Often abbreviated `OS') The
foundation software of a machine, of course; that which schedules
tasks, allocates storage, and presents a default interface to the
user between applications. The facilities an operating system
provides and its general design philosophy exert an extremely
strong influence on programming style and on the technical cultures
that grow up around its host machines. Hacker folklore has been
shaped primarily by the UNIX, ITS, TOPS-10,
TOPS-20/TWENEX, WAITS, CP/M, MS-DOS, and
Multics operating systems (most importantly by ITS and
UNIX).