1969
AT&T-owned Bell Laboratories withdraws from development of Multics, a pioneering but overly complicated time-sharing system. Some important principles in Multics were to be carried over into Unix.
Ken Thompson at Bell Labs writes the first version of an as-yet-unnamed operating system in assembly language for a DEC PDP-7 minicomputer.
1970
Thompson's operating system is named Unics, for Uniplexed Information and Computing Service, and as a pun on "emasculated Multics." (The name would later be mysteriously changed to Unix.)
1971
Unix moves to the new DEC PDP-11 minicomputer.
The first edition of the Unix Programmer's Manual, written by Thompson and Dennis Ritchie, is published.
1972
Ritchie develops the C programming language.
1973
Unix matures. The "pipe" is added to Unix; this mechanism for sharing information between two programs will influence operating systems for decades. Unix is rewritten from assembler into C.
1974
"The UNIX Timesharing System," by Ritchie and Thompson, appears in the monthly journal of the Association for Computing Machinery. The article produces the first big demand for Unix.
1976
Bell Labs programmer Mike Lesk develops UUCP (Unix-to-Unix Copy Program) for the network transfer of files, e-mail and Usenet content.
1977
Unix is ported to non-DEC hardware, including the IBM 360.
1978
Bill Joy, a graduate student at UC Berkeley, sends out copies of the first Berkeley Software Distribution (1BSD), essentially Bell Labs' Unix v6 with some add-ons. BSD becomes a rival Unix branch to AT&T's Unix; its variants and eventual descendents include FreeBSD, NetBSD, OpenBSD, DEC Ultrix, SunOS, NeXTstep/OpenStep and Mac OS X.
1980
4BSD, with DARPA sponsorship, becomes the first version of Unix to incorporate TCP/IP.
1982
Bill Joy co-founds Sun Microsystems to produce the Unix-based Sun workstation.
1983
AT&T releases the first version of the influential Unix System V, which would later become the basis for IBM's AIX and Hewlett-Packard's HP-UX.
1984
X/Open Co., a European consortium of computer makers, is formed to standardize Unix in the X/Open Portability Guide.