HP Multi-Programming Executive
MPE (Multi-Programming Executive) is a discontinued business-oriented mainframe computer real-time operating system made by Hewlett-Packard. While initially a mini-mainframe, the final high-end systems supported 12 CPUs and over 2000 simultaneous users. Description. It runs on the HP 3000 family of computers, which originally used HP custom 16-bit stack architecture CISC CPUs and were later migrated to PA-RISC where the operating system was called MPE XL. In 1983, the original version of MPE was written in a language called SPL (System Programming Language). MPE XL was written primarily in  Pascal, with some assembly language and some of the old SPL code. In 1992, the OS name was changed to MPE/iX to indicate Unix interoperability with the addition of POSIX compatibility. The discontinuance of the product line was announced in late 2001, with support from HP terminating at the end of 2010. A number of 3rd party companies still support both the hardware and software. In 2002 HP released the last version MPE/iX 7.5. Commands. Among others, MPE/iX supports the following list of common commands and programs.