ABSTRACT
In brief, an operating system is the set of programs that control a computer. Some operating systems you may have heard of are Unix (including SCO UNIX, Linux, Solaris, Irix, and FreeBSD); the Microsoft family (MS-DOS, MS-Windows, Windows/NT, Windows 2000, and Windows XP); IBM operating systems (MVS, VM, CP, OS/2); MacOS; Mach; and VMS. Some of these (Mach and Unix) have been implemented on a wide variety of computers, but most are specific to a particular architecture, such as the Digital Vax (VMS), the Intel 8086 and successors (the Microsoft family, OS/2), the Motorola 68000 and successors (MacOS), and the IBM 360 and successors (MVS, VM, CP).
