Sixth Edition Unix (also known as V6 Unix) was the first version of Unix to see wide release outside Bell Labs. Since source code was available and the license was not explicit enough to forbid it, V6 was taken up as a teaching tool, notably by the University of California at Berkeley and the University of New South Wales. While its influence was somewhat muted by the more successful Version 7 Unix, V6 was the codebase that began the BSD line of Unices. Unix or UNIX is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T Bell Labs employees including Ken Thompson, Dennis Ritchie, and Douglas McIlroy. ... Bell Telephone Laboratories or Bell Labs was originally the research and development arm of the United States Bell System, and was the premier corporate facility of its type, developing a range of revolutionary technologies from telephone switches to specialized coverings for telephone cables, to the transistor. ... Source code (commonly just source or code) is any series of statements written in some human-readable computer programming language. ... The University of California, Berkeley (also known as Cal, UC Berkeley, UCB, or simply Berkeley) is a prestigious, public, coeducational university situated in the foothills of Berkeley, California to the east of San Francisco Bay, overlooking the Golden Gate and its bridge. ... University of New South Wales The University of New South Wales is a university in Sydney, New South Wales, Australia. ... Early Unix releases were named based on the edition of the documentation that described them. ... BSD redirects here; for other uses see BSD (disambiguation). ...

V6 was also notable for the Lions Book, named after the UNSW professor John Lions who wrote it. This book was an edited selection of the main parts of the kernel as implemented for a Digital PDP-11/40, and was the main source of kernel documentation for many early Unix developers. Lions Commentary on UNIX 6th Edition, with Source Code by John Lions (1976) contains the complete source code of the 6th Edition Unix kernel plus a commentary. ... John Lions (died December 5, 1998) was an Australian computer scientist. ... Dennis Ritchie and Ken Thompson at a PDP-11 The PDP-11 was a 16-bit minicomputer sold by Digital Equipment Corp. ...

The code has been available under a BSD License under agreement from the SCO Group. The BSD license is an acronym for the Berkeley Software Distribution license agreement. ... The SCO Group, Inc. ...