Introduction to Unix The Unix Wars! Pg 1

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1 Introduction to Unix The Unix Wars! Pg 1 The Unix Wars! Ray Lockwood Points: UC Berkeley builds BSD, the Unix variant that runs workstations and ArpaNet. AT&T becomes free to commercialize Unix The Unix Wars AT&T vs. BSD AT&T's Business Environment In the 1950's, the Department of Justice prosecuted AT&T for violating the antitrust laws. The settlement of that prosecution produced a number of consent decrees; a 1957 consent decree forbade AT&T from entering the commercial computing business. As a result, the work AT&T had done on Unix was for its own in-house use; it had no value as a product because it couldn't be sold, though could be given away freely. This was the legal environment under which Bell Labs had done all of its pioneering work on Multics and Unix. ken & dmr Ken Thompson & Dennis Ritchie The ACM Paper Jump ahead to 1974 Ritchie and Thompson 1 published a paper in the Communications of the ACM titled The UNIX Time-Sharing System 2 describing its design. After that, universities all over the world beat a path to Bell Labs for a chance to try Unix for themselves. Thompson sent a tape of the latest Unix source code to whomever asked, often with a note signed love, ken. The ACM is the Association for Computing Machinery, which many of you will join. Is it UNIX or Unix? Ritchie says that spelling UNIX in all upper-case started with this 1974 ACM paper, which printed the name in small caps: UNIX. We had a new typesetter and troff had just been invented, and we were intoxicated by being able to produce small caps. Ritchie tried unsuccessfully to get the spelling changed to Unix because the word isn't an acronym. The trademark is registered as UNIX, but both capitalizations have ancient roots. University of California, Berkeley The University of California at Berkeley was especially active with operating system research, and it was the primary focus of Unix development outside of Bell Labs. Unix work at UC Berkeley caught fire when Ken Thompson taught there during a sabbatical in Photo from The Jargon File: 2 ACM paper available from

2 Introduction to Unix The Unix Wars! Pg 2 BSD Unix Other universities became interested in Berkeley's work and began asking for copies of source code. In the research lab run by graduate student Bill Joy 3 packaged a Unix version dubbed the Berkeley Software Distribution (BSD) to share with anyone who asked. BSD Unix was mostly AT&T Version 7 Unix with some additions. Berkeley was spectacularly productive with Unix development. In 1979, Berkeley's Unix had become so sophisticated (virtual memory, new editors and shells) that DARPA funded BSD as the foundation of a standard Unix to be used in other DARPA projects. Is it ARPA or DARPA? ARPA (Advanced Research Projects Agency) was established in 1958 as part of the Department of Defense. It was renamed to DARPA ( D for Defense) in 1972, then back to ARPA in 1993, and again to DARPA in Networking By 1980, Berkeley was the center of a circle of universities contributing to BSD Unix. That year, DARPA funded Berkeley to implement ARPANET's TCP/IP network protocol in BSD for the new DEC VAX computers that would serve as ARPANET hubs. Timesharing vs. Networking: Remember that Dennis Ritchie of Bell Labs talked about timesharing and the fellowship of programmers. His concept revolved around a single computer center, not a nationwide network of connected machines. Bell Labs didn't do much with networking; the network laurel rests with UC Berkeley and DARPA. The arrival of advanced networking to Unix was the turning point that brought Unix, and specifically BSD Unix, into a new legitimacy outside the academic world. Bill Joy Bill Joy wrote the vi editor, the csh shell, and went on to cofound Sun Microsystems. Ten years later, ARPANET would become today's Internet. AT&T Unix Version 7 (aka Research Unix ) spawned two major Unix variants: - BSD Unix - AT&T System V (pronounced System Five ) A New Unix Industry As university students graduated and entered industry, they took Unix with them. Bill Joy, who packaged the first BSD Unix, became a co-founder (along with three Stanford graduates) of Sun Microsystems 4 in Sun built powerful Unix workstations for engineering and scientific research. Its operating system, SunOS, was based on BSD Unix. Apollo Computer (later acquired by HP) built a workstation with a Unix-like operating system two years before Sun. IBM released its version of Unix called AIX. Silicon Graphics built Unix workstations for computer-aided drafting and design. The demand for Unix systems was healthy and growing. Sun's Founders, 1982 The letters SUN stand for Stanford University Network. 3 Photo from 4 Photo from

3 Introduction to Unix The Unix Wars! Pg 3 The Second AT&T Anti-Trust Case 1983 In 1983, the Department of Justice won its second anti-trust case against AT&T. This was the case that broke up Ma Bell into the seven Regional Bell Operating Companies. It also relieved AT&T of its original 1957 consent decree which forbade participation in the computer business. AT&T was now free to market Unix! This nearly killed Unix. Two Unix Branches AT&T's Unix before the consent decree became known as Research Unix, and had version numbers, the last of which was UNIX Version 8. After AT&T became free to commercialize Unix, it gave it the trade-name System V (pronounced System Five ), and gave it release numbers; the last was System V Release 4 (SVR4). BSD and the workstation OS's were based on AT&T Research Unix, which they licensed from AT&T. HP, IBM, and Silicon Graphics (SGI) OS's were based on AT&T System V, also licensed from AT&T. After AT&T became free to market Unix, the old-line companies (IBM and later HP) used System V as the base for their operating systems. Sun and the smaller workstation companies, on the other hand, used BSD as the base for their Unix. AT&T retained its long-distance business and Bell Labs. The Baby Bells 1. Ameritech 2. Bell Atlantic 3. BellSouth 4. NYNEX 5. Pacific Telesis 6. Southwestern Bell 7. US West Battling Standards Standards Body #1 X/Open, 1984 In 1984, a group of European vendors formed the X/Open standards group to define an interoperability standard for Unix. AT&T's Merged UNIX System SVR4, 1988 AT&T also wanted a standardized Unix and moved to converge the BSD branch of Unix with its own. To achieve this it formed a partnership with Sun, the leading BSD-based vendor. The result was Unix System V Release 4 (SVR4) in 1988 with significant compatibility with BSD. Sun eventually used SVR4 as the base of their new OS, Solaris, in 1991 to replace their original BSD-based SunOS. SVR4 was AT&T's most widely adopted release.

4 Introduction to Unix The Unix Wars! Pg 4 Standards Body #2 The Open Software Foundation (OSF), 1988 After AT&T's release of SVR4, the other US Unix vendors feared that Sun would gain too much of an advantage, so in 1988 they formed their own standards body, the Open Software Foundation (OSF), to increase their legitimacy. Standards Body #3 UNIX International (UI), 1988 This caused AT&T to form a standards body of its own, UNIX International (UI), also in A battle shaped up between the backers of OSF and UI, with X/Open keeping low. POSIX and the IEEE The IEEE is an old standards body. They created yet another standard, the Portable Operating System Interface for Unix in The Unix Wars Blunder #1 AT&T clamped down hard on others who were distributing Unix source code with the threat of lawsuit. This threat smothered the desire of universities to contribute to Unix. Unix vendors stopped cooperating with each other, too. Worse, each tried to differentiate its version of Unix to make it distinct from its competitors. This caused each company's interfaces to diverge and destroy cross-platform compatibility, which fragmented the market. The free exchange of ideas and source code stopped. Blunder #2 Vendors fixated on doing battle against AT&T and Sun, and they totally ignored Microsoft and the PC. Unix workstation vendors specialized in powerful but expensive desktop systems. They focused on scientific and engineering applications and ignored the business and home market. Early PC's weren't in the same league as workstations, but they made rapid progress while their prices steadily dropped. They had a much wider range of applications than the workstations, too. Soon the price, performance, and broad applicability of PCs relegated Unix workstations to a tiny market. PC performance increased about 60% each year. Meanwhile, AT&T focused on minicomputers and mainframes, having bought NCR (one of the Seven Dwarfs ) a few years earlier in It tried to become a large-scale system vendor; it got nowhere. The PC owned the vast bottom of the computing market, and IBM owned the top. Unix was loosing it's niche.

5 Introduction to Unix The Unix Wars! Pg 5 AT&T Finally Sues AT&T sold licenses for Unix source code for $100,000 each. BSD Inc. started selling theirs theirs for $1,000. AT&T made good on its source code threat: It sued BSD Inc. and the University of California for copyright infringement in 1992 (USL v. BSDi). In the years before the suit, however, UC Berkeley had replaced AT&T's source code in BSD with their own code, specifically to prevent licensing problems. In the end, the judge was unconvinced by AT&T, and the case was settled in BSD's favor in early The two years that the case dragged had a chilling effect on Unix adoption would-be customers didn't want to get tangled up with it. Unix almost vanished. USL is Unix System Labs, a subsidiary of AT&T responsible for Unix development and licensing. In the suit, AT&T refused to reveal which parts of BSD's source code infringed. Peace And Fewer Standards At this point, the Unix vendors realized that their threat came from the PC, not from each other and that their survival was at stake. In 1993, ATT sold Unix Systems Labs, including the rights to Unix, to Novell. The same year, Novell transferred both the Unix trademark and the Unix specification to X/Open so that Unix wouldn't be the property of any one company. In 1995 Novell sold portions of its Unix support business (though not the copyrights to the original source code itself) to The Santa Cruz Operation (SCO). This sale to SCO will be pivotal in one more battle, but with Linux. In 1994, AT&T's Unix International merged with the Open Software Foundation which in turn merged with X/Open to form the Open Group in 1996 ( (1984) X/Open (1988) Open Software Foundation (1988) Unix International (1994) (New) Open Software Foundation (1996) The Open Group

6 Introduction to Unix The Unix Wars! Pg 6 AT&T left the computer business on January 1, 1997 when it sold Bell Labs to the French firm Alcatel-Lucent, and reestablished NCR as an independent company. Unix Today Today, The Open Group owns both the UNIX trademark and the Single Unix Specification (SUS), a Unix operability standard. An operating system that passes certification requirements and pays a hefty licensing fee can brand itself as UNIX. How hefty is the licensing fee? See: Operating systems that work like Unix but aren't branded as such often call themselves Unix-like or *nix systems. Most Unix activity today revolves around a particular unbranded *nix system: Linux. The Open Group disapproves of the hyphenated use of the Unix name. What About BSD? The Berkeley Computer Science Research Group (CSRG) decided that BSD had become a burdensome effort, with too many customers to support and took away too many resources from research. In 1995, the CSRG was dissolved and BSD development at Berkeley ended. However, several BSD variants have been maintained to this day, notably: FreeBSD NetBSD OpenBSD Dragonfly BSD