This is a list of operating systems. Computer operating systems can be categorized by technology, ownership, licensing, working state, usage, and by many other characteristics. In practice, many of these groupings may overlap. Criteria for inclusion is notability, as shown either through an existing Wikipedia article or citation to a reliable source.
Proprietary Acorn Computers Arthur ARX MOS RISC iX RISC OS
Amazon Fire OS
Amiga Inc. AmigaOS AmigaOS 1.0-3.9 (Motorola 68000) AmigaOS 4 (PowerPC) Amiga Unix (a.k.a. Amix)
Amstrad AMSDOS Contiki CP/M 2.2 CP/M Plus SymbOS
Apple Apple II Apple DOS Apple Pascal ProDOS GS/OS GNO/ME Contiki Apple III Apple SOS Apple Lisa Mac Classic Mac OS A/UX (UNIX System V with BSD extensions) Copland MkLinux Pink Rhapsody macOS (formerly Mac OS X and OS X) macOS Server (formerly Mac OS X Server and OS X Server) Apple Network Server IBM AIX (Apple-customized) Apple MessagePad Newton OS iPhone and iPod Touch iOS (formerly iPhone OS) iPad iPadOS Apple Watch watchOS Apple TV tvOS Embedded operating systems bridgeOS Apple Vision Pro visionOS Embedded operating systems A/ROSE iPod software (unnamed embedded OS for iPod) Unnamed NetBSD variant for Airport Extreme and Time Capsule
Apollo Computer, Hewlett-Packard Domain/OS – One of the first network-based systems. Run on Apollo/Domain hardware. Later bought by Hewlett-Packard.
Atari Atari DOS (for 8-bit computers) Atari TOS Atari MultiTOS Contiki (for 8-bit, ST, Portfolio)
BAE Systems XTS-400
Be Inc. BeOS BeIA BeOS r5.1d0 magnussoft ZETA (based on BeOS r5.1d0 source code, developed by yellowTAB)
Bell Labs Unix ("Ken's new system," for its creator (Ken Thompson), officially Unics and then Unix, the prototypic operating system created in Bell Labs in 1969 that formed the basis for the Unix family of operating systems) UNIX Time-Sharing System v1 UNIX Time-Sharing System v2 UNIX Time-Sharing System v3 UNIX Time-Sharing System v4 UNIX Time-Sharing System v5 UNIX Time-Sharing System v6 MINI-UNIX PWB/UNIX USG CB Unix UNIX Time-Sharing System v7 (It is from Version 7 Unix (and, to an extent, its descendants listed below) that almost all Unix-based and Unix-like operating systems descend.) Unix System III Unix System IV Unix System V Unix System V Releases 2.0, 3.0, 3.2, 4.0, and 4.2 UNIX Time-Sharing System v8 UNIX Time-Sharing System v9 UNIX Time-Sharing System v10
Non-Unix Operating Systems: BESYS Plan 9 from Bell Labs Inferno
Burroughs Corporation, Unisys Burroughs MCP
CII Siris 8
Commodore International GEOS AmigaOS AROS Research Operating System
Control Data Corporation Lower 3000 series SCOPE (Supervisory Control Of Program Execution)
Upper 3000 series SCOPE (Supervisory Control Of Program Execution) Drum SCOPE
6x00 and related Cyber Chippewa Operating System (COS) MACE (Mansfield and Cahlander Executive) Kronos (Kronographic OS) NOS (Network Operating System) NOS/VE (NOS Virtual Environment) SCOPE (Supervisory Control Of Program Execution) NOS/BE NOS Batch Environment SIPROS (Simultaneous Processing Operating System)
Star-100 Multiple Console Time Sharing System (MCTS), from General Motors Research
CloudMosa Puffin OS
Convergent Technologies Convergent Technologies Operating System (CTOS) – later acquired by Unisys
Cromemco Cromemco DOS (CDOS) – a Disk Operating system compatible with CP/M Cromix – a multitasking, multi-user, Unix-like OS for Cromemco microcomputers with Z80A and/or 68000 CPU
Data General AOS for 16-bit Data General Eclipse computers and AOS/VS for 32-bit (MV series) Eclipses, MP/AOS for microNOVA-based computers DG/UX RDOS Real-time Disk Operating System, with variants: RTOS and DOS (not related to PC DOS, MS-DOS etc.)
Datapoint CTOS Cassette Tape Operating System for the Datapoint 2200 DOS Disk Operating System for the Datapoint 2200, 5500, and 1100
DDC-I, Inc. Deos – Time & Space Partitioned RTOS, Certified to DO-178B, Level A since 1998 HeartOS – POSIX-based Hard Real-Time Operating System
Digital Research, Inc. CP/M CP/M CP/M for Intel 8080/8085 and Zilog Z80 Personal CP/M, a refinement of CP/M CP/M Plus with BDOS 3.0 CP/M-68K CP/M for Motorola 68000 CP/M-8000 CP/M for Zilog Z8000 CP/M-86 CP/M for Intel 8088/8086 CP/M-86 Plus Personal CP/M-86 MP/M Multi-user version of CP/M-80 MP/M II MP/M-86 Multi-user version of CP/M-86 MP/M 8-16, a dual-processor variant of MP/M for 8086 and 8080 CPUs. Concurrent CP/M, the successor of CP/M-80 and MP/M-80 Concurrent CP/M-86, the successor of CP/M-86 and MP/M-86 Concurrent CP/M 8-16, a dual-processor variant of Concurrent CP/M for 8086 and 8080 CPUs. Concurrent CP/M-68K, a variant for the 68000 DOS Concurrent DOS, the successor of Concurrent CP/M-86 with PC-MODE Concurrent PC DOS, a Concurrent DOS variant for IBM compatible PCs Concurrent DOS 8-16, a dual-processor variant of Concurrent DOS for 8086 and 8080 CPUs Concurrent DOS 286 Concurrent DOS XM, a real-mode variant of Concurrent DOS with EEMS support Concurrent DOS 386 Concurrent DOS 386/MGE, a Concurrent DOS 386 variant with advanced graphics terminal capabilities Concurrent DOS 68K, a port of Concurrent DOS to Motorola 68000 CPUs with DOS source code portability capabilities FlexOS 1.0 – 2.34, a derivative of Concurrent DOS 286 FlexOS 186, a variant of FlexOS for terminals FlexOS 286, a variant of FlexOS for hosts Siemens S5-DOS/MT, an industrial control system based on FlexOS IBM 4680 OS, a POS operating system based on FlexOS IBM 4690 OS, a POS operating system based on FlexOS Toshiba 4690 OS, a POS operating system based on IBM 4690 OS and FlexOS FlexOS 386, a later variant of FlexOS for hosts IBM 4690 OS, a POS operating system based on FlexOS Toshiba 4690 OS, a POS operating system based on IBM 4690 OS and FlexOS FlexOS 68K, a derivative of Concurrent DOS 68K Multiuser DOS, the successor of Concurrent DOS 386 CCI Multiuser DOS Datapac Multiuser DOS Datapac System Manager, a derivative of Datapac Multiuser DOS IMS Multiuser DOS IMS REAL/32, a derivative of Multiuser DOS IMS REAL/NG, the successor of REAL/32 DOS Plus 1.1 – 2.1, a single-user, multi-tasking system derived from Concurrent DOS 4.1 – 5.0 DR-DOS 3.31 – 6.0, a single-user, single-tasking native DOS derived from Concurrent DOS 6.0 Novell PalmDOS 1.0 Novell "Star Trek" Novell DOS 7, a single-user, multi-tasking system derived from DR DOS Caldera OpenDOS 7.01 Caldera DR-DOS 7.02 and higher
Digital Equipment Corporation, Compaq, Hewlett-Packard, Hewlett Packard Enterprise Batch-11/DOS-11 OS/8 RSTS/E – multi-user time-sharing OS for PDP-11s RSX-11 – multiuser, multitasking OS for PDP-11s RT-11 – single user OS for PDP-11 TOPS-10 – for the PDP-10 TENEX – an ancestor of TOPS-20 from BBN, for the PDP-10 TOPS-20 – for the PDP-10 DEC MICA – for the DEC PRISM Digital UNIX – derived from OSF/1, became HP's Tru64 UNIX Ultrix VMS – originally by DEC (now by VMS Software Inc.) for the VAX mini-computer range; later renamed OpenVMS and ported to Alpha, and subsequently ported to Intel Itanium and then to x86-64 WAITS – for the PDP-6 and PDP-10
ENEA AB OSE – Flexible, small footprint, high-performance RTOS for control processors
Fujitsu Towns OS XSP OS/IV MSP MSP-EX
GEC Computers COS DOS OS4000
General Electric, Honeywell, Bull Real-Time Multiprogramming Operating System GCOS Multics
ChromiumOS is an open source operating system development version of ChromeOS. Both operating systems are based on the Linux kernel. ChromeOS is designed to work exclusively with web applications, though has been updated to run Android apps with full support for Google Play Store. Announced on July 7, 2009, ChromeOS is currently publicly available and was released summer 2011. The ChromeOS source code was released on November 19, 2009, under the BSD license as ChromiumOS. Container-Optimized OS (COS) is an operating system that is optimized for running Docker containers, based on ChromiumOS. Android is an operating system for mobile devices. It consists of Android Runtime (userland) with Linux (kernel), with its Linux kernel modified to add drivers for mobile device hardware and to remove unused Vanilla Linux drivers. Android TV gLinux, a Linux distribution that Google uses internally Fuchsia is a capability-based real-time operating system (RTOS) scalable to universal devices, in early development, from the tiniest embedded hardware, wristwatches, tablets to the largest personal computers. Unlike ChromeOS and Android, it is not based on the Linux kernel, but instead began on a new microkernel called "Zircon", derived from "Little Kernel". Wear OS a version of Google's Android operating system designed for smartwatches and other wearables. GooglebookOS (ALOS)
Green Hills Software INTEGRITY – Reliable Operating system INTEGRITY-178B – A DO-178B certified version of INTEGRITY. μ-velOSity – A lightweight microkernel.
Harris Computer Systems Vulcan O/S – Proprietary O/S for Harris Computer Systems (HCX) CX/UX – Proprietary UNIX based OS for Harris' computers (MCX)
Heathkit, Zenith Data Systems HDOS – ran on the H8 and Heath/Zenith Z-89 series HT-11 – a modified version of RT-11 that ran on the Heathkit H11
Hewlett-Packard, Hewlett Packard Enterprise HP Multi-Programming Executive (MPE, MPE/XL, and MPE/iX) – runs on HP 3000 and HP e3000 mini-computers HP-UX – runs on HP9000 and Itanium servers (from small to mainframe-class computers)
Honeywell CP-6, CP-V work-alike for Honeywell Level/66
Huawei HarmonyOS HarmonyOS NEXT LiteOS EulerOS
Intel Corporation iRMX – real-time operating system originally created to support the Intel 8080 and 8086 processor families in embedded applications. ISIS, ISIS-II – "Intel Systems Implementation Supervisor" was an environment for development of software within the Intel microprocessor family in the early 1980s on their Intellec Microcomputer Development System and clones. ISIS-II worked with 8 inch floppy disks and had an editor, cross-assemblers, a linker, an object locator, debugger, compilers for PL/M, a BASIC interpreter, etc. and allowed file management through a console. iMAX 432 - an operating system for systems based on Intel's iAPX 432 architecture.
IBM
On early mainframes: 1410, 7010, 704, 709, 7090, 7094, 7040, 7044, 7030 BESYS – for the IBM 7090 Compatible Time-Sharing System (CTSS) – developed at MIT's Computation Center for use on a modified IBM 7094 FORTRAN Monitor System (FMS) – for the IBM 709 and 7090 GM OS & GM-NAA I/O – for the IBM 704 IBSYS – tape based operating system for IBM 7090 and IBM 7094 7040/7044 Operating System (16/32K) - 7040-PR-150 IJMON – A bootable serial I/O monitor for loading programs for the IBM 1400 series 1410 Processor Operating System (PR-155) for the 1410 and 7010 SHARE Operating System (SOS) – for the IBM 704 and 709 University of Michigan Executive System (UMES) – for the IBM 704, 709, and 7090)
On S/360, S/370, and successor mainframes OS/360 and successors on IBM S/360, S/370, and successor mainframes OS/360 (first official OS targeted for the System/360 architecture) PCP (Primary Control Program, a kernel and a ground breaking automatic space allocating file system) MFT (original Multi-programming with a Fixed number of Tasks, replaced by MFT II) MFT II (Multi-Programming with a Fixed number of Tasks, had up to 15 fixed size application partitions, plus partitions for system tasks, initially defined at boot time but redefinable by operator command) MVT (Multi-Programming with a Variable number of Tasks, had up to 15 application regions defined dynamically, plus additional regions for system tasks) M65MP (MVT with support for a multiprocessor 360/65)