operating system

n. [techspeak] (Often abbreviated OS ) The foundation software of a machine;
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). See also
timesharing.

