High Quality Content by WIKIPEDIA articles! HP-UX (Hewlett-Packard UniX) is Hewlett-Packard`s proprietary implementation of the Unix operating system, based on UNIX System V (initially System III) and first released in 1984. Recent versions support the HP 9000 series of computer systems, based on the PA-RISC processor architecture, and HP Integrity systems, based on Intel`s Itanium architecture.