A Backgrounder on IEEE Std 1003.1
This paper is derived from the Preface to the standard and provides information on the background, audience and purpose of IEEE Std 1003.1.

IEEE Std 1003.1 (known as "POSIX.1") has been jointly developed by the IEEE and The Open Group. It is simultaneously an IEEE Standard, an ISO/IEC Standard, and an Open Group Technical Standard.


The developers of this standard represent a cross section of hardware manufacturers, vendors of operating systems and other software development tools, software designers, consultants, academics, authors, applications programmers, and others.

Conceptually, this standard describes a set of fundamental services needed for the efficient construction of application programs. Access to these services has been provided by defining an interface, using the C programming language, a command interpreter, and common utility programs that establish standard semantics and syntax. Since this interface enables application writers to write portable applications-it was developed with that goal in mind-it has been designated POSIX,1 an acronym for Portable Operating System Interface.

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 and the parts of ISO/IEC 9945. In earlier editions of the IEEE standard, the term POSIX was used as a synonym for IEEE Std 1003.1-1988. A preferred term, POSIX.1, emerged. This maintained the advantages of readability of the symbol ``POSIX'' without being ambiguous with the POSIX family of standards.


The intended audience for this standard is all persons concerned with an industry-wide standard operating system based on the UNIX system. This includes at least four groups of people:

  1. Persons buying hardware and software systems

  2. Persons managing companies that are deciding on future corporate computing directions

  3. Persons implementing operating systems, and especially

  4. Persons developing applications where portability is an objective


Several principles guided the development of this standard:


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.



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