Version 7 Unix

Seventh Edition Unix, also called Version 7 Unix, Version 7 or just V7, was an important early release of the Unix operating system. V7, released in 1979, was the last Bell Laboratories release to see widespread distribution before the commercialization of Unix by AT&T Corporation in the early 1980s. V7 was originally developed for Digital Equipment Corporation's PDP-11 minicomputers and was later ported to other platforms.

Unix versions from Bell Labs were designated by the edition of the user's manual with which they were accompanied. The Seventh Edition was preceded by Sixth Edition, which was the first version to be widely distributed outside of the Labs. Development of the Research Unix line continued with the Eighth Edition, which incorporated development from 4.1BSD, through the Tenth Edition, after which the Bell Labs researchers concentrated on developing Plan 9.

V7 was the first readily portable version of Unix. As this was the era of minicomputers, with their many architectural variations, and also the dawning of the market for 16-bit microprocessors, many ports were completed within the first few years of its release. The first Sun workstations (then based on the Motorola 68010) ran a V7 port by UniSoft; the first version of Xenix for the Intel 8086 was derived from V7; and Onyx Systems soon produced a Zilog Z8000 computer running V7. The VAX port of V7, called UNIX/32V, was the direct ancestor of the popular 4BSD family of Unix systems. The group at University of Wollongong that had ported V6 to the Interdata 7/32 ported V7 to that machine as well, which was sold commercially under the name Edition VII by Interdata and Perkin-Elmer (now known as PerkinElmer) on most models of the 3200 series, the first commercial UNIX offering.

DEC distributed their own PDP-11 version of V7, called V7M (for modified). V7M, developed by DEC's original Unix Engineering Group (UEG), contained many enhancements to the kernel for the PDP-11 line of computers including significantly improved hardware error recovery and many additional device drivers. UEG evolved into the group that later developed Ultrix.

Due to its power yet elegant simplicity, many old-time Unix users fondly (and with a good amount of nostalgia) remember V7 as the pinnacle of Unix development and have dubbed it "the last true Unix," an improvement over all preceding and following Unices.