POSIX

Family of IEEE standards for compatibility between operating systems

The Portable Operating System Interface (POSIX; IPA:) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. In order to define a level of compatibility, POSIX specifies many aspects of functionality that can be classified as application programming interface (API), command-line shell, and shell commands, originally derived from commonly-found Unix APIs, shells, and commands (partly because Unix was considered manufacturer-neutral). Today, many systems conform to the standard – including branded Unix systems, Unix-like systems, and many systems that were historically unrelated to Unix.

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