HP-UX

HP-UX (aka Hewlett-Packard UniX) is Hewlett-Packard's copyrighted application of the UNIX operating system, built on UNIX System V (at the outset System III) which was first introduced in the year of 1984. However, the versions which are recently released basically support the HP 9000 series of computer systems, built on the PA-RISC processor architecture, and HP Integrity systems, as well as on Intel's Itanium architecture.

Not surprisingly, the versions which were released in previously i.e. of HP-UX supported the HP Integral PC and HP 9000 Series 200, 300, and 400 computer systems those were built on the Motorola 68000 series of processors, in addition to the HP 9000 Series 500 computers which were made on HP's patented FOCUS processor architecture.

HP-UX was the first UNIX that provided access control lists for file access permissions as a substitute to the typical UNIX permission system. HP-UX was also one of the principal UNIX systems that comprised of a built-in logical volume manager. It had been associated since long with Veritas Software, and incorporates VxFS as the major file system.