Definition of Posix in US English:


(also POSIX)


  • A set of formal descriptions that provide a standard for the design of operating systems, especially ones which are compatible with Unix.

    • ‘If the community can sort out some issues between Linux and Posix, the user community may choose to adopt those interfaces, but they will vote with their feet not in a consortium.’
    • ‘QNX is also Posix compliant, so there is lots of software that almost works under it.’
    • ‘‘You can implement Posix today with the limited swap instructions that are there today,’ he said.’
    • ‘Carrier-grade features to be added include support for Posix compliant threading, diskless blade systems, improved systems responsiveness, and advanced debugging and systems analysis.’
    • ‘I still think that something like POSIX capabilities is important, but I'm not so sure anymore that Posix capabilities is the right way to go about solving the problem.’


1980s: from the initial letters of portable operating system + -ix suggested by Unix.