Unix wars

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Unix genealogy tree

The Unix wars were struggles between vendors to set a standard for the Unix operating system in the late 1980s and early 1990s.

Origins

Although

PC/IX, among others; AT&T's System V, which it sought to establish as the new Unix standard;[2] and the Berkeley Software Distribution (BSD). All were derived from AT&T's Research Unix
but had diverged considerably. Further, each vendor's version of Unix was different to some degree.

For example, at a mid-1980s

Usenix
conference, many AT&T staff had buttons that read "System V: Consider it Standard" and a number of major vendors were promoting products based on System V. On the other hand, System V did not yet have TCP/IP networking built-in, while BSD 4.2 did; vendors of engineering workstations were nearly all using BSD, and posters reading "4.2 > V" were available.

Several vendors formed the

System V Release 4 (SVR4) which still lives to this day through its derivative OpenIndiana.[3]

While this decision was applauded by customers and the trade press, certain other Unix licensees feared Sun would be unduly advantaged. They formed the Open Software Foundation (OSF) in 1988. The same year, AT&T and another group of licensees responded by forming Unix International (UI). Technical issues soon took a back seat to vicious and public commercial competition between the two "open" versions of Unix, with X/Open holding the middle ground.

A 1990 study of various Unix versions' reliability found that in each version, between a quarter and a third of operating system utilities could be made to

fuzzing; the researchers attributed this, in part, to the "race for features, power, and performance" resulting from BSD–System V rivalry, which left developers little time to worry about reliability.[4]

Standardization

The 1988

C library
functions beyond what was included in the forthcoming C standard; later it expanded to specify other aspects of the system environment. POSIX specified a "lowest common denominator" that could be met by both System V and BSD-based variants, as well as some non-Unix systems, with a reasonable amount of effort.

In March 1993, the major participants in UI and OSF formed the Common Open Software Environment (COSE) alliance, effectively marking the end of the most significant era of the Unix wars. In June, AT&T sold its Unix assets to Novell, and in October Novell transferred the Unix brand to X/Open.

In 1996, X/Open and the new OSF merged to form the

Open Group. COSE work such as the Single UNIX Specification
, the current standard for branded Unix, is now the responsibility of the Open Group, which also controls the current POSIX standards.

Since then, occasional bursts of Unix factionalism have broken out, such as the

new SCO, formerly Caldera
.

BSD and the rise of Linux

BSD worked to purge copyrighted AT&T code from their version between 1989 and 1994. During this time, various open-source BSD x86 derivatives took shape, starting with

Eric Raymond, BSD systems can be considered "genetic Unix", if not "trademark Unix".[6]

During BSD's period of legal turmoil (1992–94),[7] the nearly-complete GNU operating system was made operational by the inclusion of the Linux kernel and lumped together under the label "Linux". GNU had been written from scratch to avoid copyright issues. Linux systems broadly aim for compatibility with POSIX.

See also

References

  1. ^ Fiedler, Ryan (October 1983). "The Unix Tutorial / Part 3: Unix in the Microcomputer Marketplace". BYTE. p. 132. Retrieved January 30, 2015.
  2. ^ Shea, Tom (February 20, 1984). "New developments may decide battle over Unix". InfoWorld. pp. 43–45. Archived from the original on February 16, 2021. Retrieved February 25, 2016.
  3. ^ "Home". www.openindiana.org. Retrieved May 9, 2023.
  4. S2CID 14313707. Archived
    (PDF) from the original on October 24, 2018. Retrieved September 10, 2015.
  5. ^ "Mac OS X Leopard Achieves UNIX 03 Product Standard Certification". Archived from the original on June 9, 2011. Retrieved July 28, 2009.
  6. ^ "Microsoft Buys into SCO Group's Unix". Archived from the original on August 17, 2009. Retrieved March 20, 2009.
  7. ^ Unix System Laboratories v. Berkeley Software, 832 F. Supp. 790 (D.N.J. 1993).

Sources

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