Timeline: 40 Years Of Unix

Some milestones of the Unix operating system's four-decades-long history

1 2 Page 2
Page 2 of 2

AT&T publishes the System V Interface Definition, an attempt to set a standard for how Unix works.


Rick Rashid and colleagues at Carnegie Mellon University create the first version of Mach, a replacement kernel for BSD Unix.


AT&T Bell Labs and Sun Microsystems announce plans to co-develop a system to unify the two major Unix branches.

Andrew Tanenbaum writes Minix, an open-source Unix clone for use in computer science classrooms.


The "Unix Wars" are under way. In response to the AT&T/Sun partnership, rival Unix vendors including DEC, HP and IBM form the Open Software Foundation (OSF) to develop open Unix standards. AT&T and its partners then form their own standards group, Unix International.

The IEEE publishes Posix (Portable Operating System Interface for Unix), a set of standards for Unix interfaces.


Unix System Labs, an AT&T Bell Labs subsidiary, releases System V Release 4 (SVR4), its collaboration with Sun that unifies System V, BSD, SunOS and Xenix.


The OSF releases its SVR4 competitor, OSF/1, which is based on Mach and BSD.


Sun announces Solaris, an operating system based on SVR4.

Linus Torvalds writes Linux, an open-source OS kernel inspired by Minix.


The Linux kernel is combined with GNU to create the free GNU/Linux operating system, which many refer to as simply "Linux."


AT&T sells its subsidiary Unix System Laboratories and all Unix rights to Novell. Later that year, Novell transfers the Unix trademark to the X/Open group.

Microsoft introduces Windows NT, a powerful, 32-bit multiprocessor operating system. Fear of NT spurs true Unix-standardization efforts.


X/Open merges with the OSF to form The Open Group.


Thompson and Ritchie receive the National Medal of Technology from President Clinton.


The Open Group announces Version 3 of the Single Unix Specification.

Sources: A Quarter Century of UNIX, by Peter H. Salus; Microsoft; AT&T; The Open Group; Wikipedia and other sources

Main story: Unix turns 40: The past, present and future of a revolutionary OS

Copyright © 2009 IDG Communications, Inc.

1 2 Page 2
Page 2 of 2
7 inconvenient truths about the hybrid work trend
Shop Tech Products at Amazon