Portable Operating System Interface

operating system, standard (POSIX) A set of IEEE standards

designed to provide application portability between Unix

variants. IEEE 1003.1 defines a Unix-like operating system

interface, IEEE 1003.2 defines the shell and utilities and

IEEE 1003.4 defines real-time extensions.

["More UNIX For Dummies", ISBN: 1-56884-361-5] says it stands

for "Portable Operating System Interface with an X thrown in

to make it sound cooler."

(1997-12-04)