Real Time Operating System, ran on 5 NASA custom System/360-75s) TOS/360 (Tape Operating System) TSS/360 (IBM's Time Sharing System) MUSIC/SP (developed by McGill University for IBM System/370) ORVYL and WYLBUR (developed by Stanford University for IBM System/360) On PC and Intel x86 based architectures PC DOS, IBM DOS PC DOS 1.x, 2.x, 3.x (developed jointly with Microsoft) IBM DOS 4.x, 5.0 (developed jointly with Microsoft) PC DOS 6.1, 6.3, 7, 2000, 7.10 OS/2 OS/2 1.x (developed jointly with Microsoft) OS/2 2.x OS/2 Warp 3 (ported to PPC via Workplace OS) OS/2 Warp 4 eComStation (Warp 4.5/Workspace on Demand, rebundled by Serenity Systems International) ArcaOS (Warp 4.52 based system sold by Arca Noae, LLC) IBM 4680 OS version 1 to 4, a POS operating system based on Digital Research's Concurrent DOS 286 and FlexOS 286 1.xx IBM 4690 OS version 1 to 6.3, a successor to 4680 OS based on Novell's FlexOS 286/FlexOS 386 2.3x Toshiba 4690 OS version 6.4, a successor to 4690 OS 6.3 Unix-like on PS/2 AIX (IBM's Advanced Interactive eXecutive, a System V Unix version) On other hardware platforms IBM Series/1 EDX (Event Driven Executive) RPS (Realtime Programming System) CPS (Control Programming Support, subset of RPS) SerIX (Unix on Series/1) IBM 1130 DMS (Disk Monitor System) IBM 1800 TSX (Time Sharing eXecutive) MPX (Multi Programming eXecutive) IBM 8100 DPCX (Distributed Processing Control eXecutive) DPPX (Distributed Processing Programming Executive) IBM System/3 DMS (Disk Management System) IBM System/34, IBM System/36 SSP (System Support Program) IBM System/38 CPF (Control Program Facility) IBM System/88 Stratus VOS (developed by Stratus, and used for IBM System/88, Original equipment manufacturer from Stratus) IBM AS/400, iSeries, System i, IBM Power Systems IBM i (previously known as OS/400 and i5/OS, descendant of System/38 CPF, includes System/36 SSP and AIX environment) UNIX on IBM RT PC AOS (a BSD Unix version, not related to Data General AOS) AIX (Advanced Interactive eXecutive, a System V Unix version) UNIX on POWER ISA, PowerPC, and Power ISA AIX (Advanced Interactive eXecutive, a System V Unix version) Others Workplace OS (a microkernel based operating system including OS/2, developed and canceled in the 1990s) K42 (open-source research operating system on PowerPC or x86 based cache-coherent multiprocessor systems) Dynix (developed by Sequent, and used for IBM NUMA-Q too) International Computers Limited J and MultiJob – for the System 4 series mainframes GEORGE 2/3/4 GEneral ORGanisational Environment – used by ICL 1900 series mainframes