In late 1960, the Massachusetts Institute of Technology, the Bell Laboratories of AT & T and General Electric worked on operating system experimental called Multics (Uniplexed Information and Computing System according to AbbreviationFinder), developed to run on a mainframe (mainframe) model GE-645. The goal of the project was to develop a large interactive operating system that featured many innovations, including improvements to security policies. The project managed to produce production versions, but the first versions had poor performance. AT & T’s Bell Labs decided to divest itself and dedicate its resources to other projects.
One of the Bell Labs team programmers, Ken Thompson, continued to work for the GE-635 computer and wrote a game called Space Travel. However, he found the game to be slow on the General Electric machine and really expensive, something like US $ 75. for each game.
Thus, Thompson wrote the program, assisted by Dennis Ritchie, in newly assembly language, to be execute on a computer DEC PDP-7. This experience, together with the work he did for the Multics project, led Thompson to begin creating a new operating system for the DEC PDP-7.
Thompson and Ritchie led a group of programmers, including Rudd Canaday at Bell Labs, to develop both the file system and the multitasking operating system itself. To this, they added a shell (or shell) and a small set of programs. The project was called UNICS, as acronym A iplexed Information and C omputing S ystem, it served only two users (according to Andrew Tanenbaum, it was just a user. The authorship of this acronym is attributed to Brian Kernighan, since it was a hack by Multics. Given the popularity of a play on words that considered UNICS a neutered MULTICS system (since eunuchs, in English, is a homophone of UNICS), the name was changed to UNIX, giving rise to the legacy that continues to this day.
Until then, there had been no financial support from Bell Labs, but that changed when the Computer Science Research Group decided to use UNIX on a machine superior to the PDP-7. Thompson and Ritchie were able to fulfill the request to add tools that would allow word processing to UNIX on a PDP-11/20 machine, and as a result they obtained financial support from Bell Labs. This was how for the first time, in 1970, there was officially talk of the UNIX operating system running on a PDP-11/20. A program for formatting texts (runoff) and a text editor were included in it. Both the operating system and the programs were written in the assembly language of the PDP-11/20. This initial “word processing system”, comprised of both the operating system, the runoff system and the text editor, was used at Bell Labs to process the patent applications they received. Soon, runoff evolved into troff, the first electronic publishing program to allow typesetting. The 3 of November of 1971 Thomson and Ritchie published a manual programming of UNIX (original title in English: “UNIX Programmer’s Manual”).
In 1972 the decision was made to write UNIX again, but this time in the C programming language. This change meant that UNIX could be easily modified to work on other computers (thus, it became portable) and thus other variations could be developed by other programmers. Now, the code was more concise and compact, which resulted in an increase in the speed of UNIX development. AT&T made UNIX available to universities and companies, including the United States government, through licenses.
One of these licenses was granted to the Department of Computing at the University of California, based in Berkeley. In 1975 this institution developed and published its own replacement for UNIX, known as Berkeley Software Distribution (BSD), which became a strong competitor to AT & T’s UNIX family.
Meanwhile, AT&T created a business division called Unix Systems Laboratories for commercial exploitation of the operating system. Development continued, with the delivery of versions 4, 5 and 6 in the course of 1975. These versions include the pipes or pipes, which allowed give development a modular guidance on the basis of the code, achieving further increase the speed of development. As early as 1978, about 600 or more machines were running some of the different incarnations of UNIX.
Version 7, the last widely distributed version of the original UNIX, came into circulation in 1979. Versions 8, 9, and 10 were developed during the 1980s, but their circulation was limited to a few universities, despite reports describing the new work being published. The results of this research served as the basis for the creation of Plan 9 from Bell Labs, a new portable and distributed operating system, designed to be the successor to UNIX under investigation by Bell Labs.
AT&T then began development of UNIX System III, based on version 7, as a commercial dye variant and thus sold the product directly. The first version was released in 1981. Despite this, the subsidiary company Western Electric continued to sell old versions of Unix based on the different versions up to the seventh. To end the confusion with all the divergent versions, AT&T decided to combine several versions developed in different universities and companies, giving rise in 1983 to Unix System V Release 1. This version presented features such as the Vi editor and the curses library, developed by Berkeley Software Distribution at the University of California, Berkeley. It also had compatibility with DECcompany’s VAX machines.
In 1993, the Novell Company acquired AT & T’s Unix Systems Laboratories division along with its intellectual property. This occurred at a sensitive time when Unix Systems Laboratories was contesting a lawsuit in court against BSD for copyright infringement, disclosure of secrets, and trademark infringement.
BSD not only won the case but changed tables discovering that large portions of the code had been copied illegally BSD UNIX System V. In reality, the intellectual property of Novell (just acquired from Unix Systems Laboratories) was limited to a few source files. The corresponding counter-claim resulted in an out-of-court settlement, the terms of which remain secret at the request of Novell.
Around the same time, a computer science student named Linus Torvalds developed a kernel for computers with an Intel x86 processor architecture that mimicked many of the functionality of UNIX and released it in open source form in 1991, under the name of Linux. In 1992, the GNU Project began using the Linux kernel alongside its programs.
In 1995, Novell sold its commercial UNIX division. SCO continues to market System V in its UnixWare product, which for a time was renamed OpenUnix, although it has reverted to the UnixWare name.