Several research and development operating systems have been ported to PA-RISC between the late 1980s and late 1990s, many of them Mach microkernel-based.| www.openpa.net
OpenBSD is an Unix-like open source operating system for PA-RISC and supports 32-bit HP 9000 workstations and some 64-bit computers.| www.openpa.net
HP-RT was a real-time operating system for HP PA-RISC VME boards.| www.openpa.net
Ports of several commercial operating systems including Windows NT and NetWare to PA-RISC had been attempted in the 1990s.| www.openpa.net
The HP 9000 S-Class/Convex Exemplar SPP2000 are large scalable PA-RISC computing servers and the direct predecessors of the later HP V-Class.| www.openpa.net
HP-UX is HP’s commercial Unix operating system for PA-RISC computers, version 11i from the 2000s runs on most PA-RISC and Itanium computers from HP.| www.openpa.net
The first HP PA-RISC computer systems were released by HP in the 1980s with the HP 9000/800 Series, which were all server systems.| www.openpa.net
Many Unix and similar operating systems were available for PA-RISC from the 1980s on, first HP-UX, followed by many Mach and BSD research projects.| www.openpa.net
Most PA-RISC operating systems were commercial Unix, Unix-like derivates or open source projects, with different designs ported and developed for PA-RISC.| www.openpa.net
The Convex Exemplar SPP1000, SPP1200 and SPP1600 are scalable 32-bit mainframe computing systems, with either PA-7100 or PA-7200 processors.| www.openpa.net