Operating_system

Interacts directly with hardware and provides a virtual machine on which programs execute. Manages processes, memory and hardware devices. The operating system is generally considered to be composed of a kernel and a bundle of user applications.

Examples include Atlas, Multics, Vax/VMS, CP/M, DOS, System V, Solaris, Linux and Windows NT.

Most modern operating systems are heavily influenced by

Mach.

Most operating systems in use in the late 1990s are

based on:

Unix (Aix, HP-UX, Solaris, Linux)

VaxVMS (Windows NT, Windows 2000)

System 360 (IBM)

An operating system is generally classified as being monolithic or micro-kernal.