What is Unix

v A multi-task and multi-user Operating System

v Developed in 1969 at AT&T’s Bell Labs by

·        Ken Thompson (Unix)

·        Dennis Ritchie (C)

·        Douglas Mcllroy (Pipes - Do one thing, do it well)

v Some other variants: System V, Solaris, SCO Unix, SunOS, 4.4BSD, FreeBSD, NetBSD, OpenBSD, BSDI

v You can have many users logged into a system simultaneously, each running many programs.

v It's the kernel's job to keep each process and user separate and to regulate access to system hardware, including cpu, memory, disk and other I/O devices.

What is Unix