HP-UX
HP-UX (from "Hewlett Packard Unix") is a discontinued proprietary implementation of the Unix operating system developed by Hewlett Packard Enterprise, now out of standard support (Mature Support on HPE Integrity without Sustaining Engineering through at least 2028); the final versions support HPE Integrity Servers, based on Intel's Itanium architecture. It is based on Unix System V (initially System III) and first released in 1984.