Softpanorama (slightly skeptical) Open Source Software Educational Society

May the source be with you, but remember the KISS principle ;-) Softpanorama Search

Nikolai Bezroukov. Portraits of Open Source Pioneers

For readers with high sensitivity to grammar errors access to this page is explicitly prohibited :-)

Unix Wars of 1987-1993: POSIX as a result of struggle of AT&T and Sun against the rest of the world

In 1987, AT&T entered an alliance to develop a standard Unix version with Sun Microsystems, the leading vendor of the BSD Unix variant. As the result of this move in 1989, USL released SVR4, which integrated the System V and BSD Unix baselines that brought  the best features from the many versions of UNIX into a single unified system. While many applauded this decision, one group of UNIX licensees expressed the fear that Sun would have a huge commercial advantage over the rest of the licensees.

The concerned group in 1988 formed a special interest group, the Open Systems Foundation (OSF), to lobby for an "open" UNIX within the UNIX community. Soon several large companies -- who at the time were promoting their own proprietary operating systems in competition to UNIX -- also joined the OSF.

Not to be outstaged, AT&T, Sun and several other Unix licensees formed their own group, UNIX International.

The technical issues soon took a back seat to what can be charitably described as competitive maneuverings which got the historic name of  "UNIX wars." Those wars were not without positive results: they lead to creation of  Portable Operating System Interface Specifications (POSIX).

 At the beginning the Open Group's Single UNIX Specification was separate from the official IEEE POSIX.  Later it cane under IEEE umbrella and the result was POSIX  specifications. Here is relevant quote from POSIX.1 FAQ

Q0. What is POSIX? What is POSIX.1?

POSIX is a registered trademark of the IEEE.

POSIX is an acronym for

Although originated to refer to the original IEEE Std 1003.1-1988, the name POSIX more correctly refers to a family of related standards: IEEE Std 1003.n (where n is a number) and the parts of ISO/IEC 9945. The term POSIX was originally used as a synonym for IEEE Std 1003.1-1988. A preferred term for that standard, POSIX.1, emerged. This maintained the advantages of readability of the symbol ``POSIX'' without being ambiguous with the POSIX family of standards.

For a full listing of the project numbers see PASC Standing Document SD11.

The name POSIX was suggested by Richard Stallman. It is expected to be pronounced pahz-icks, as in positive, not poh-six, or other variations. The pronunciation has been published in an attempt to promulgate a standardized way of referring to a standard operating system interface.

The latest version of the POSIX.1 standard is IEEE Std 1003.1, 2004 Edition, developed by the Austin Group (see later). For further information on the background, audience and purpose of POSIX.1 see the following document:

URL:http://www.opengroup.org/austin/papers/backgrounder.html.

Linus became interested in POSIX in mid-1991, when he was already in the middle of the creation of version 0.01 of Linux:

> From: torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
> Newsgroups: comp.os.minix
> Subject: Gcc-1.40 and a posix-question
> Message-ID: <1991 Jul3.100050.9886@klaava.Helsinki.FI>
> Date: 3 Jul 91 10:00:50 GMT
>
> Hello netlanders,
>
> Due to a project I'm working on (in minix), I'm interested in the posix
> standard definition. Could somebody please point me to a (preferably)
> machine-readable format of the latest posix rules? Ftp-sites would be
> nice