Luettelo käyttöjärjestelmistä

Tämä on luettelo käyttöjärjestelmistä.

Kaupalliset/suljetut

Acorn Computers
 Arthur
 ARX
 MOS
 RISC iX
 RISC OS

Amiga Inc.
 AmigaOS
 AmigaOS 1.0-3.9 (Motorola 68000)
 AmigaOS 4 (PowerPC)

 Amiga UNIX (eli Amix)

Apple Inc.
 Apple II -perhe
 Apple DOS
 Apple Pascal
 ProDOS
 GS/OS
 Apple III
 Apple SOS
 Apple Lisa
 Lisa Workshop
 Lisa Operating System
 Apple Macintosh
 Mac OS
 A/UX (UNIX System V BSD-lisäyksillä)
 Rhapsody
 NeXTSTEP
 macOS (ennen Mac OS X ja OS X)
 macOS Server (ennen Mac OS X Server ja OS X Server)
 Apple Network Server
 IBM AIX (Applen mukauttamana)
 Apple MessagePad
 Newton OS
 iPhone, iPod Touch, iPad
 iOS
 Apple Watch
 watchOS
 Apple TV
 tvOS
 Sulautetut käyttöjärjestelmät
 A/ROSE
 iPod software (nimetön sulautettu käyttöjärjestelmä iPodille)
 Nimetön NetBSD-variantti Airport Extremeä ja Time Capsulea varten

Apollo Computer
 Domain/OS : Yksi ensimmäisistä verkkopohjaisista järjestelmistä. Apollo/Domain-laitteistolla. Myöhemmin Hewlett-Packardin ostama.

Atari
 Atari DOS (8-bittisille tietokoneille)
 Atari TOS
 Atari MultiTOS

BAE Systems
 XTS-400

Be Inc.
 BeOS
 BeIA
 BeOS r5.1d0
 magnussoft ZETA (perustuu BeOS r5.1d0:n lähdekoodiin, kehittänyt yellowTAB)

Bell Labs
 Unix ("Kenin uusi järjestelmä" tekijänsä Ken Thompsonin mukaan, virallisesti Unics sitten Unix, Bell Labsissa 1969 käyttöjärjestelmä joka toimi prototyyppinä Unix-pohjaisille käyttöjärjestelmille)
 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 (Juuri Version 7 Unixiin (ja osin myös sen alaversioista) pohjautuvat kaikki nykyiset Unixiin pohjautuvat sekä Unixin kaltaiset käyttöjärjestelmät.)
 Unix System III
 Unix System IV
 Unix System V
 Unix System V -versiot 2.0, 3.0, 3.2, 4.0 ja 4.2
 UNIX Time-Sharing System v8
 UNIX TIme-Sharing System v9
 UNIX Time-Sharing System v10

Unixiin liittymättömät:
 BESYS
 Plan 9 from Bell Labs

Bull SAS
 General Comprehensive Operating System (GCOS)

Burroughs Corporation, Unisys
 Burroughs MCP

Control Data Corporation
 Chippewa Operating System (COS)
 MACE (Mansfield and Cahlander Executive)
 Kronos (Kronographic OS)
 NOS (Network Operating System)
 NOS/BE NOS Batch Environment
 NOS/VE NOS Virtual Environment
 SCOPE (Supervisory Control Of Program Execution)
 SIPROS (Simultaneous Processing Operating System)
 EP/IX (Enhanced Performance Unix)

Convergent Technologies
 Convergent Technologies Operating System (Unisys osti myöhemmin)

Data General
 AOS 16-bittisille Data General Eclipse -tietokoneille ja AOS/VS 32-bittisille (MV-sarjan) Eclipseille, MP/AOS microNOVA-pohjaisille tietokoneille
 DG/UX
 RDOS Real-time Disk Operating System, muunnoksia: RTOS ja DOS (ei sukua PC DOS:lle, MS-DOS:lle jne.)

DataPoint
 CTOS Z80-pohjaisille, Cassette Tape Operating System aikaisille työpöytäjärjestelmille. Pystyy peräti 8 samanaikaiseen käyttäjään. DataPoint DOS:n korvaama.
 DOS Intel 808x/80x86-pohjainen, Disk Operating System työpöytäjärjestelmille. Pystyy peräti 32 käyttäjään solmua kohden. Tuki usein tarkoitusta varten rakennettua hienostunutta solmuverkostoa. DOS-nimeä käytettiin näiden järjestelmien kirjautumisruuduissa ennen kuin IBM, Microsoft ja muut tekivät nimestä kuuluisan.

DDC-I, Inc.
 Deos aika- ja avaruusosioitu RTOS, DO-178B, Level A -sertifikoitu vuodesta 1998
 HeartOS POSIX-pohjainen kova reaaliaikainen käyttöjärjestelmä

Digital Research, Inc.
 CP/M
 CP/M CP/M Intel 8080/8085:lle ja Zilog Z80:lle
 Personal CP/M, CP/M:n muunnos
 CP/M Plus BDOS 3.0:n kanssa
 CP/M-68K CP/M Motorola 68000:lle
 CP/M-8000 CP/M Zilog Z8000:lle
 CP/M-86 CP/M Intel 8088/8086:lle
 CP/M-86 Plus
 Personal CP/M-86
 MP/M monta käyttäjää tukeva CP/M-80-muunnos
 MP/M II
 MP/M-86 monta käyttäjää tukeva CP/M-86-muunnos
 MP/M 8-16, kaksoissuoritinmuunnos MP/M:stä 8086- ja 8080-suorittimille.
 Concurrent CP/M, CP/M-80:n ja MP/M-80:n seuraaja
 Concurrent CP/M-86, CP/M-86:n ja MP/M-86:n seuraaja
 Concurrent CP/M 8-16, kaksoissuoritinmuunnos Concurrent CP/M:stä 8086- ja 8080-suorittimille.
 Concurrent CP/M-68K, muunnos 68000-suorittimelle
 DOS
 Concurrent DOS, Concurrent CP/M-86:n seuraaja. mukana PC-MODE
 Concurrent PC DOS, Concurrent DOS -muunnos IBM PC -yhteensopiville tietokoneille
 Concurrent DOS 8-16, kaksoissuoritinmuunnos Concurrent DOS:sta 8086- ja 8080-suorittimille
 Concurrent DOS 286
 Concurrent DOS XM, Concurrent DOS:n muunnos reaalitilalle EEMS-tuella
 Concurrent DOS 386
 Concurrent DOS 386/MGE, Concurrent DOS 386:n muunnos edistyneillä graafisten päätteiden toiminnoilla
 Concurrent DOS 68K, Concurrent DOS:n käännös Motorola 68000 -suorittimelle, DOS-lähdekoodi käännettävissä
 FlexOS 1.0 – 2.34, Concurrent DOS 286:een pohjautuva
 FlexOS 186, FlexOS:n muunnos päätteille
 FlexOS 286, FlexOS:n muunnos isäntäkoneille
 Siemens S5-DOS/MT, FlexOS:iin pohjautuva teollisuusohjausjärjestelmille
 IBM 4680 OS, FlexOS:iin pohjautuva myyntipistekäyttöjärjestelmä
 Toshiba 4690 OS, FlexOS:iin ja IBM 4690 OS:iin pohjautuva myyntipistekäyttöjärjestelmä
 FlexOS 386, FlexOS:n myöhempi muunnos isäntäkoneille
 IBM 4690 OS, FlexOS:iin pohjautuva myyntipistekäyttöjärjestelmä
 Toshiba 4690 OS, FlexOS:iin ja IBM 4690 OS:iin pohjautuva myyntipistekäyttöjärjestelmä
 FlexOS 68K, Concurrent DOS 68K:n muunnos
 Multiuser DOS, Concurrent DOS 386:n seuraaja
 CCI Multiuser DOS
 Datapac Multiuser DOS
 Datapac System Manager, Datapac Multiuser DOS:n muunnos
 IMS Multiuser DOS
 IMS REAL/32, Multiuser DOS:n muunnos
 IMS REAL/NG, REAL/32:n seuraaja
 DOS Plus 1.1 – 2.1, yhden käyttäjän moniajokäyttöjärjestelmä, pohjautuu Concurrent DOS:in versioihin 4.1 – 5.0
 DR-DOS 3.31 – 6.0, yhden käyttäjän natiivi DOS-käyttöjärjestelmä, pohjautuu Concurrent DOS:in versioon 6.0
 Novell PalmDOS 1.0
 Novell "Star Trek"
 Novell DOS 7, yhden käyttäjän moniajokäyttöjärjestelmä, pohjautuu DR DOS:iin
 Caldera OpenDOS 7.01
 Caldera DR-DOS 7.02 ja korkeammat

Digital Equipment Corporation, Tandem Computers, Compaq, Hewlett-Packard
 Domain/OS (alun perin Aegis, HP:n ostamalta Apollo Computerilta)
 HP-UX
 Multi-Programming Executive (HP:lta)
 NonStop
 OS/8
 RSTS/E (monta käyttäjää tukeva osituskäyttöjärjestelmä PDP-11:lle)
 RSX-11 (monta käyttäjää tukeva moniajokäyttöjärjestelmä for PDP-11:lle)
 RT-11 (yhden käyttäjän käyttöjärjestelmä PDP-11:lle)
 TOPS-10 (PDP-10:lle)
 TENEX (TOPS-20-käyttöjärjestelmän edeltäjä BBN:ltä, PDP-10:lle)
 TOPS-20 (PDP-10:lle)
 Digital UNIX (OSF/1:een pohjautuva, myöhemmin HP:n Tru64 UNIX)
 Ultrix
 VMS (aluksi DEC:n ja HP:n, nyt VMS Software Inc.) VAX-minitietokonesarjalle, Alpha:lle ja Itanium i2 and i4:lle; myöhemmin nimeltään OpenVMS)
 WAITS (PDP-6:lle ja PDP-10:lle)

ENEA AB
 OSE Mukautuva, pienen jalanjäljen korkean suorituskyvyn reaaliaikainen käyttöjärjestelmä ohjaussuorittimille

Fujitsu
 Towns OS

General Electric
 Real-Time Multiprogramming Operating System

Google

 Google Chrome OS on suunniteltu yksinomaan verkkosovelluksille. Siitä ilmoitettiin ekan kerran 7. heinäkuuta 2009, on nyt julkisesti saatavilla ja julkaistiin kesällä 2011. Chrome OS:n lähdekoodi julkaistiin 19. marraskuuta 2009, Chromium OS:n tapaan BSD-lisenssillä.
 Chromium OS on avoimen lähdekoodin kehitysversio Chrome OS:stä. Molemmat pohjautuvat Linux-ytimeen.
 Android on käyttöjärjestelmä mobiililaitteille. Se koostuu Android Runtime:stä (käyttäjäpuoli) ja Linuxista (ydin), jota on muokattu lisäämällä ajureita mobiililaitteistolle sekä poistamalla käyttämättömiä Linux-ajureita.

Green Hills Software
 INTEGRITY Reliable Operating system
 INTEGRITY-178B DO-178B-sertifikoitu versio INTEGRITY:stä.
 µ-velOSity Kevyt mikroydin.

Heathkit, Zenith Data Systems
 HDOS; pyöri H8- ja Heath/Zenith Z-89 -sarjan laitteilla
 HT-11 (mukautettu versio RT-11:stä) pyöri Heathkit H11 -laitteilla

Hewlett-Packard
 HP Multi-Programming Executive (MPE, MPE/XL ja MPE/iX) pyörivät HP 3000- ja HP e3000 -minitietokoneilla
 HP-UX; pyörii HP9000- ja Itanium-palvelimilla – pienistä tietokoneista suurtietokoneisiin
 NonStop OS; pyörii HP:n NonStop-sarjan Itanium-palvelimilla

Honeywell
 Multics
 GCOS
 CP-6

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.

IBM

Varhaiset suurtietokoneet: 1400, 1800, 701, 704, 709, 7090, 7094
 BESYS (for the IBM 7090)
 CTSS (The Compatible Time-Sharing System, developed at MIT's Computation Center for use on a modified IBM 7094)
 GM OS & GM-NAA I/O (for the IBM 704)
 IBSYS (tape based operating system for IBM 7090 and IBM 7094)
 IJMON (A bootable serial I/O monitor for loading programs for IBM 1400 and IBM 1800)
 SOS (SHARE Operating System, for the IBM 704 and 709)
 UMES (University of Michigan Executive System, for the IBM 704, 709, and 7090)

S/360, S/370 ja seuraavat suurtietokoneet
 OS/360 and successors on IBM S/360, S/370, and successor mainframes
 OS/360 (first official OS targeted for the System/360 architecture),Saw customer installations of the following variations:
 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 Variable Tasks, had up to 15 application regions defined dynamically, plus additional regions for system tasks)
 OS/VS (port of OS/360 targeted for the System/370 virtual memory architecture, "OS/370" is not correct name for OS/VS1 and OS/VS2, but rather refers to OS/VS2 MVS and MVS/SP Version 1),Customer installations in the following variations:
 SVS (Single Virtual Storage, both VS1 & VS2 began as SVS systems)
 OS/VS1 (Operating System/Virtual Storage 1, Virtual-memory version of MFT II)
 OS/VS2 (Operating System/Virtual Storage 2, Virtual-memory version of OS/MVT but without multiprocessing support)
 OS/VS2 R2 (called Multiple Virtual Storage, MVS, eliminated most need for VS1)
 MVS/SE (MVS System Extensions)
 MVS/SP (MVS System Product)
 MVS/XA (MVS/SP V2. MVS supported eXtended Architecture, 31-bit addressing)
 MVS/ESA (MVS supported Enterprise System Architecture, horizontal addressing extensions: data only address spaces called Dataspaces; a Unix environment was available starting with MVS/ESA V4R3)
 OS/390 (Upgrade from MVS, with an additional Unix environment)
 z/OS (OS/390 supported z/Architecture, 64-bit addressing)
 DOS/360 and successors on IBM S/360, S/370, and successor mainframes
 BOS/360 (early interim version of DOS/360, briefly available at a few Alpha & Beta System/360 sites)
 TOS/360 (similar to BOS above and more fleeting, able to boot and run from 2x00 series tape drives)
 DOS/360 (Disk Operating System (DOS), multi-programming system with up to 3 partitions, first commonly available OS for System/360)
 DOS/360/RJE (DOS/360 with a control program extension that provided for the monitoring of remote job entry hardware (card reader & printer) connected by dedicated phone lines)
 DOS/VS (First DOS offered on System/370 systems, provided virtual storage)
 DOS/VSE (also known as VSE, upgrade of DOS/VS, up to 14 fixed size processing partitions )
 VSE/SP (program product replacing DOS/VSE and VSE/AF)
 VSE/ESA (DOS/VSE extended virtual memory support to 32-bit addresses (Extended System Architecture)).
 z/VSE  (latest version of the four decades old DOS lineage, supports 64-bit addresses, multiprocessing, multiprogramming, SNA, TCP/IP, and some virtual machine features in support of Linux workloads)
 CP/CMS (Control Program/Cambridge Monitor System) and successors on IBM S/360, S/370, and successor mainframes
 CP-40/CMS (for System/360 Model 40)
 CP-67/CMS (for System/360 Model 67)
 VM/370 (Virtual Machine / Conversational Monitor System, virtual memory operating system for System/370)
 VM/XA  (VM/eXtended Architecture for System/370 with extended virtual memory)
 VM/ESA (Virtual Machine / Extended System Architecture, added 31-bit addressing to VM series)
 z/VM (z/Architecture version of the VM OS with 64-bit addressing)
 TPF Line (Transaction Processing Facility) on IBM S/360, S/370, and successor mainframes (largely used by airlines)
 ACP (Airline Control Program)
 TPF (Transaction Processing Facility)
 z/TPF (z/Architecture extension)
 Unix-like on IBM S/360, S/370, and successor mainframes
 AIX/370 (IBM's Advanced Interactive eXecutive, a System V Unix version)
 AIX/ESA (IBM's Advanced Interactive eXecutive, a System V Unix version)
 OpenSolaris for IBM System z
 UTS (developed by Amdahl)
 z/Linux
 Others on IBM S/360, S/370, and successor mainframes:
 BOS/360 (Basic Operating System)
 MTS (Michigan Terminal System, developed by a group of universities in the US, Canada, and the UK for the IBM System/360 Model 67, System/370 series, and compatible mainframes)
 RTOS/360 (IBM's Real Time Operating System, ran on 5 NASA custom System/360-75s)"RTOS: extending OS/360 for real time spaceflight control", J. L. Johnstone, in AFIPS '69 (Spring) Proceedings of the May 14–16, 1969, spring joint computer conference, pages 15-27.
 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)

PC-yhteensopivissa
 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
 Katso myös: MS-DOS ja Windows
 OS/2
 OS/2 1.x (developed jointly with Microsoft)
 OS/2 2.x
 OS/2 Warp 3
 OS/2 Warp 4
 eComStation (Warp 4.5/Workspace on Demand, rebundled by Serenity Systems International)
 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

Muilla laitealustoilla
 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)
 AS/400, iSeries, System i, Power Systems i Edition
 OS/400 (descendant of System/38 CPF, include System/36 SSP environment)
 i5/OS (extends OS/400 with significant interoperability features)
 IBM i (extends i5/OS)
 UNIX on IBM POWER
 AIX (Advanced Interactive eXecutive, System V Unix-versio)
 AOS (a BSD Unix version, not related to Data General AOS)
 Others
 IBM Workplace OS (Mikroydin-pohjainen käyttöjärjestelmä, kehitetty ja peruttu 1990-luvulla)
 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 ja MultiJob System 4 -sarjan suurtietokoneille
 GEORGE 2/3/4 GEneral ORGanisational Environment, ICL 1900-sarjan suurtietokoneissa
 Executive, 1900- ja 290x-sarjan minitietokoneissa. Executiven mukautettua versiota käytettiin myös osana GEORGE 3- ja 4-järjestelmiä.
 TME, ME29-minitietokoneissa
 ICL VME, mukaan lukien aikaiset versiot VME/B and VME/2900, ICL 2900 -sarjan sekä Series 39 -sarjan suurtietokoneissa, S3-kielellä toteutettu
 VME/K hyvin pienillä 2900-koneilla

Jide
Remix OS

Lynx Real-time Systems, LynuxWorks, Lynx Software Technologies
 LynxOS

Micrium Inc.
 MicroC/OS-II (pieni ennakoiva tärkeysjärjestyspohjainen moniajoydin)
 MicroC/OS-III (pieni ennakoiva tärkeysjärjestyspohjainen moniajoydin, tehtävien ja tärkeystasojen määrä rajoittamaton, kiertovuorottelu)

Microsoft Corporation
 Xenix (Unixin lisensoitu versio; lisensoitiin SCO:lle vuonna 1987)
 MSX-DOS (MS Japan -osaston kehittämä, MSX-sarjan 8-bittisille tietokoneille)
 MS-DOS (yhdessä IBM;n kanssa, versiot 1.0–6.22)
 Windows (16- ja 32-bittinen ennakoiva sekä yhteistyömoniajo, pyörii MS-DOS:n päällä)
 Windows 1.0 (Windows 1)
 Windows 2.0 (Windows 2 – erillinen versio i386-suorittimelle)
 Windows 3.0 (Windows 3)
 Windows 3.1x (Windows 3.1)
 Windows for Workgroups 3.1 (koodinimi Snowball)
 Windows 3.2 (vain kiinaksi)
 Windows for Workgroups 3.11
 Windows 95 (koodinimi Chicago – Windows 4.0)
 Windows 98 (koodinimi Memphis – Windows 4.1)
 Windows Millennium Edition (Windows ME – Windows 4.9)
 Windows NT (täysin 32- tai 64-bittinen ydin, ei perustu MS-DOS:iin)
 Windows NT 3.1
 Windows NT 3.5
 Windows NT 3.51
 Windows NT 4.0
 Windows 2000 (Windows NT 5.0)
 Windows XP (Windows NT 5.1)
 Windows Server 2003 (Windows NT 5.2)
 Windows Fundamentals for Legacy PCs (Windows XP:hen pohjautuva)
 Windows Vista (Windows NT 6.0)
 Windows Azure (Cloud OS Platform) 2009
 Windows Home Server (Windows Server 2003:een pohjautuva)
 Windows Server 2008 (Windows Vistaan pohjautuva)
 Windows 7 (Windows NT 6.1)
 Windows Server 2008 R2 (Windows 7:ään pohjautuva)
 Windows Home Server 2011 (Windows Server 2008 R2:een pohjautuva)
 Windows Server 2012 (Windows 8:aan pohjautuva)
 Windows 8 (Windows NT 6.2)
 Windows Phone 8
 Windows 8.1 (Windows NT 6.3)
 Windows Server 2012 R2 (Windows 8.1:een pohjautuva)
 Xbox Onen käyttöjärjestelmä
 Windows Phone 8.1
 Windows 10 (Windows NT 10.0)
 Windows 10 Mobile
 Windows Server 2016
 Windows 11
 Windows CE (käyttöjärjestelmä taskulaitteille, sulautetuille laitteille ja reaaliaikaisiin sovelluksiin, muistuttaa muita Windows-versioita)
 Windows CE 3.0
 Windows CE 5.0
 Windows CE 6.0
 Windows Mobile (Windows CE:hen pohjautuva, mutta pienempi kokomitta)
 Windows Phone 7
 Singularity – pääosin hallitulla koodilla (C#) kirjoitettu tutkimuskäyttöjärjestelmä
 Midori – hallitun koodin käyttöjärjestelmä
 Xbox 360:n käyttöjärjestelmä
 Xbox Onen käyttöjärjestelmä

MontaVista
 MontaVista Mobilinux

NCR Corporation
 TMX – Transaction Management eXecutive
 IMOS - Interactive Multiprogramming Operating System (noin 1978), NCR Century 8200 -sarjan minitietokoneille
 VRX - Virtual Resource eXecutive

Nintendo
 es on alun perin Nintendon ja myöhemmin Esrillen kehittämä käyttöjärjestelmä. Sen lähdekoodi on avointa. Järjestelmä pyörii natiivisti x86-alustoilla.

Novell
 NetWare  network operating system providing high-performance network services. Has been superseded by Open Enterprise Server line, which can be based on NetWare or Linux to provide the same set of services.
 UnixWare
 Novell "SuperNOS", a never released merge of NetWare and UnixWare
 Novell "Corsair"
 Novell "Exposé"
 Open Enterprise Server, the successor to NetWare.

Quadros Systems
 RTXC Quadros RTOS proprietary C-based RTOS used in embedded systems

RCA
 TSOS, first OS supporting virtual addressing of the main storage and support for both timeshare and batch interface

RoweBots
 DSPnano RTOS 8/16 Bit Ultra Tiny Embedded Linux Compatible RTOS
 Unison RTOS 32 Bit Open Standards, Linux Compatible, Ultra Tiny Size, Modularity, POSIX-compliant RTOS that supports a variety of wireless modules and provides a complete set of security protocols

Samsung Electronics
 Bada
 Tizen

SCO, SCO Group
 Xenix, Unix System III based distribution for the Intel 8086/8088 architecture
 Xenix 286, Unix System V Release 2 based distribution for the Intel 80286 architecture
 Xenix 386, Unix System V Release 2 based distribution for the Intel 80386 architecture
 SCO Unix, SCO UNIX System V/386 was the first volume commercial product licensed by AT&T to use the UNIX System trademark (1989). Derived from AT&T System V Release 3.2 with an infusion of Xenix device drivers and utilities plus most of the SVR4 features
 SCO Open Desktop, the first 32-bit graphical user interface for UNIX Systems running on Intel processor-based computers. Based on SCO Unix
 SCO OpenServer 5, AT&T UNIX System V Release 3 based
 SCO OpenServer 6, SVR5 (UnixWare 7) based kernel with SCO OpenServer 5 application and binary compatibility, system administration, and user environments
 UnixWare
 UnixWare 2.x, based on AT&T System V Release 4.2MP
 UnixWare 7, UnixWare 2 kernel plus parts of 3.2v5 (UnixWare 2 + OpenServer 5 = UnixWare 7). Referred to by SCO as SVR5

Scientific Data Systems (SDS)
 Berkeley Timesharing System for the SDS 940

 Sciopta Systems GmbH 
 SCIOPTA Pre-emptive, priority-based real-time kernel (IEC61508 certified)

 SYSGO 
 PikeOS is a certified real time operating system for safety and security critical embedded systems

Tandy Corporation
 TRSDOS; A floppy-disk-oriented OS supplied by Tandy/Radio Shack for their Z80-based line of personal computers. Eventually renamed as LS-DOS or LDOS.
 Color BASIC; A ROM-based OS created by Microsoft for the TRS-80 Color Computer.
 NewDos/80; A third-party OS for Tandy's TRS-80 personal computers.
 DeskMate; Operating system created by Tandy Corporation and introduced with the Tandy 1000 computer.

TCSC (later NCSC)
 Edos – enhanced version of IBM's DOS/360 (and later DOS/VS and DOS/VSE) operating system for System/360 and System/370 IBM mainframes

 Texas Instruments 
 TI-RTOS Kernel; Real-time operating system for TI's embedded devices.

 TRON Project 
 TRON (avoin RTOS kerneli)
 T-Kernel

Unisys
 Unisys MCP
 Unisys OS 2200 operating system

UNIVAC, Unisys
 EXEC I
 EXEC II
 EXEC 8 Ran on 1100 series.
 VS/9, successor to RCA TSOS

 Wang Laboratories 
 WPS Wang Word Processing System. Micro-code based system.
 OIS Wang Office Information System. Successor to the WPS. Combined the WPS and VP/MVP systems.
 Wang VS Operating System (VSOS) – used on the VS line of minicomputer systems.

WICAT
 WICAT Multiuser Computer System (WMCS). MC-68K multiuser O/S for their proprietary microcomputers, used mainly for CBT systems

Wind River Systems
 VxWorks Small footprint, scalable, high-performance RTOS for embedded microprocessor based systems.http://www.windriver.com/products/vxworks/

Muita

Lisp-based
 Lisp Machines, Inc. (also known as LMI) used an operating system written in MIT's Lisp Machine Lisp.
 Symbolics Genera written in a systems dialect of the Lisp programming language called ZetaLisp and Symbolics Common Lisp. Genera was ported to a virtual machine for the DEC Alpha line of computers.
 Texas Instruments' Explorer Lisp machine workstations also had systems code written in Lisp Machine Lisp.
 Xerox 1100 series of Lisp machines used an operating system also written in Interlisp, and was also ported to a virtual machine called "Medley."
 PilOS Stand alone operating system. It is a full blown 64-bit PicoLisp runs directly on a standard x86-64 PC hardware.

Non-standard language-based
 Pilot operating system (used in Xerox Star workstations) was written in the Mesa programming language.
 PERQ Operating System (POS) was written in PERQ Pascal.

Other proprietary non-Unix-like
 Эльбрус-1 (Elbrus-1) and Эльбрус-2 used for application, job control, system programming,  implemented in uЭль-76 (AL-76).
 EOS; developed by ETA Systems for use in their ETA-10 line of supercomputers
 EMBOS; developed by Elxsi for use on their mini-supercomputers
 GCOS is a proprietary Operating System originally developed by General Electric
 MAI Basic Four; An OS implementing Business Basic from MAI Systems.
 Michigan Terminal System; Developed by a group of universities in the US, Canada, and the UK for use on the IBM System/360 Model 67, the System/370 series, and compatible mainframes
 MUSIC/SP; an operating system developed for the S/370, running normally under VM
 OS ES; an operating system for ES EVM
 PC-MOS/386; DOS-like, but multiuser/multitasking
 Prolog-Dispatcher; used to control Soviet Buran space ship.
 SINTRAN III; an operating system used with Norsk Data computers.
 SkyOS; commercial desktop OS for PCs
 THEOS
 TSX-32; a 32-bit operating system for x86 platform.
 TX990/TXDS, DX10 and DNOS; proprietary operating systems for TI-990 minicomputers

Other proprietary Unix-like and POSIX-compliant
 Aegis (Apollo Computer)
 Amiga Unix (Amiga-versio Unix System V julkaisuversiosta 3.2 Amiga A2500UX:lle ja SVR4-julkaisusta Amiga A3000UX:lle. Aloitettu vuonna 1990, viimeinen versio vuonna 1992.)
 Coherent (Unixin kaltainen käyttöjärjestelmä Mark Williamsilta henkilökohtaisille tietokoneille)
 DC/OSx (DataCenter/OSx—an operating system developed by Pyramid Technology for its MIPS-based systems)
 DG/UX (Data General Corp)
 DNIX from DIAB
 DSPnano RTOS (POSIX nanokernel, DSP Optimized, Open Source)
 HeliOS developed and sold by Perihelion Software mainly for transputer based systems
 Interactive Unix (a port of the UNIX System V operating system for Intel x86 by Interactive Systems Corporation)
 IRIX from SGI
 MeikOS
 NeXTSTEP (developed by NeXT; a Unix-based OS based on the Mach microkernel)
 OS-9 Unix-like RTOS. (OS from Microware for Motorola 6809 based microcomputers)
 OS9/68K Unix-like RTOS. (OS from Microware for Motorola 680x0 based microcomputers; based on OS-9)
 OS-9000 Unix-like RTOS. (OS from Microware for Intel x86 based microcomputers; based on OS-9, written in C)
 OSF/1 (developed into a commercial offering by Digital Equipment Corporation)
 OpenStep
 QNX (POSIX, microkernel OS; usually a real time embedded OS)
 Rhapsody (an early form of Mac OS X)
 RISC iX – derived from BSD 4.3, by Acorn computers, for their ARM family of machines
 RISC/os (a port by MIPS Technologies of 4.3BSD for its MIPS-based computers)
 RMX
 SCO UNIX (from SCO, bought by Caldera who renamed themselves SCO Group)
 SINIX (a port by SNI of Unix to the MIPS architecture)
 Solaris (Sun Microsystemsiltä, Oraclen ostama; System V-pohjainen korvaaja SunOS:lle)
 SunOS (BSD-pohjainen Unix-käyttöjärjestelmä varhaiselle Sun Microsystemsin laitteistolle)
 SUPER-UX (a port of System V Release 4.2MP with features adopted from BSD and Linux for NEC SX architecture supercomputers)
 System V (a release of AT&T Unix, 'SVR4' was the 4th minor release)
 System V/AT, 386 (The first version of AT&T System V UNIX on the IBM 286 and 386 PCs, ported and sold by Microport)
 Trusted Solaris (Solaris with kernel and other enhancements to support multilevel security)
 UniFLEX (Unix-like OS from TSC for DMA-capable, extended addresses, Motorola 6809 based computers; e.g. SWTPC, GIMIX and others)
 Unicos (Unix-versio Crayn supertietokoneille, pääasiassa vektorilaskentaan)
 UTX-32 (Developed by Gould CSD (Computer System Division), a Unix-based OS that included both BSD and System V characteristics. It was one of the first Unix based systems to receive NSA's C2 security level certification.)
 Zenix, Zenith corporations Unix (a popular USA electronics maker at the time)

Ei-kaupalliset/avoimet

Unixin-kaltaiset
Tutkimus ja muut POSIX-yhteensopivat
 MINIX (study OS developed by Andrew S. Tanenbaum in the Netherlands)
 Plan 9 from Bell Labs (distributed OS developed at Bell Labs, based on original Unix design principles yet functionally different and going much further)
 Inferno (distributed OS derived from Plan 9, originally from Bell Labs)
 Plan B (distributed OS derived from Plan 9 and Off++ microkernel)
 Unix (Bell Labs:ssa 1970-luvulla kehitetty käyttöjärjestelmä, Ken Thompsonin aloittama)
 Xinu (Study OS developed by Douglas E. Comer in the United States)
Ilmaiset ja avoimen lähdekoodin
 BSD (Berkeley Software Distribution, a variant of Unix for DEC VAX hardware)
 FreeBSD (one of the outgrowths of UC Regents' abandonment of CSRG's 'BSD Unix')
 DragonFlyBSD, forked from FreeBSD 4.8
 MidnightBSD, forked from FreeBSD 6.1
 Darwin, created by Apple using FreeBSD and NeXTSTEP
 PC-BSD
 GhostBSD
 TrueOS (previously known as PC-BSD)
 NetBSD (an embedded device BSD variant)
 OpenBSD forked from NetBSD
 Bitrig forked from OpenBSD
 GNU
 Linux
 Luettelo Linux-jakelupaketeista
 Android x86
 Cray Linux Environment
 illumos, contains original Unix (SVR4) code derived from the OpenSolaris (discontinued by Oracle in favor of Solaris 11 Express)
 OpenIndiana, operates under the illumos Foundation. Uses the illumos kernel, which is a derivative of OS/Net, which is basically an OpenSolaris/Solaris kernel with the bulk of the drivers, core libraries, and basic utilities.
 Nexenta OS, based on the illumos kernel with Ubuntu packages
 SmartOS, an illumos distribution for cloud computing with Kernel-based Virtual Machine integration.
 RTEMS (Real-Time Executive for Multiprocessor Systems)
 Syllable Desktop
 Univention Corporate Server
 VSTa
 FMI/OS, successor of VSTa
Muut
 Plurix
 TUNIS (University of Toronto)

Non-Unix-like

Research
 Amoeba (research OS by Andrew S. Tanenbaum)
 Croquet
 EROS microkernel, capability-based
 CapROS microkernel EROS successor.
 Coyotos microkernel EROS successor, goal: be first formally verified OS.
 HelenOS research and experimental operating system
 House – Haskell User's Operating System and Environment, research OS written in Haskell and C
 ILIOS Research OS designed for routing
 L4 second generation microkernel
 Mach (from OS kernel research at Carnegie Mellon University; see NeXTSTEP)
 Nemesis Cambridge University research OS – detailed quality of service abilities
 Spring (research OS from Sun Microsystems)
 THE multiprogramming system by Dijkstra in 1968, at the Eindhoven University of Technology in the Netherlands, introduced the first form of software-based memory segmentation, freeing programmers from being forced to use actual physical locations
 V from Stanford, early 1980s

Free and open source
 Cosmos (written in C#)
 FreeDOS (open source DOS variant)
 Haiku (open source inspired by BeOS, under development)
 Ghost OS (written in Assembly, C/C++)
 ITS written by MIT students (for the PDP-6 and PDP-10) (written in MIDAS)
 osFree OS/2 Warp open source clone.
 OSv (written in C++)
 Phantom OS (persistent object oriented)
 ReactOS, open source OS designed to be binary compatible with Windows NT and its variants (Windows XP, Windows 2000, etc.); currently in development phase
 SharpOS (written in .NET C#)
 TempleOS (written in HolyC)
 Redox OS (written in Rust)http://www.redox-os.org/

Disk operating systems (DOS)

 86-DOS (developed at Seattle Computer Products by Tim Paterson for the new Intel 808x CPUs; licensed to Microsoft, became PC DOS/MS-DOS. Also known by its working title QDOS.)
 PC DOS (IBM's DOS variant, developed jointly with Microsoft, versions 1.0–7.0, 2000, 7.10)
 MS-DOS (Microsoft's DOS variant for OEM, developed jointly with IBM, versions 1.x–6.22 Microsoft's now abandoned DOS variant)
 Concurrent CP/M-86 3.1 (BDOS 3.1) with PC-MODE (Digital Research's successor of CP/M-86 and MP/M-86)
 Concurrent DOS 3.1-4.1 (BDOS 3.1-4.1)
 Concurrent PC DOS 3.2 (BDOS 3.2) (Concurrent DOS variant for IBM compatible PCs)
 DOS Plus 1.1, 1.2 (BDOS 4.1), 2.1 (BDOS 5.0) (single-user, multi-tasking system derived from Concurrent DOS 4.1-5.0)
 Concurrent DOS 8-16 (dual-processor variant of Concurrent DOS for 8086 and 8080 CPUs)
 Concurrent DOS 286 1.x
 FlexOS 1.00-2.34 (derivative of Concurrent DOS 286)
 FlexOS 186 (variant of FlexOS for terminals)
 FlexOS 286 (variant of FlexOS for hosts)
 Siemens S5-DOS/MT (industrial control system based on FlexOS)
 IBM 4680 OS (POS operating system based on FlexOS)
 IBM 4690 OS (POS operating system based on FlexOS)
 Toshiba 4690 OS (POS operating system based on IBM 4690 OS and FlexOS)
 FlexOS 386 (later variant of FlexOS for hosts)
 IBM 4690 OS (POS operating system based on FlexOS)
 Toshiba 4690 OS (POS operating system based on IBM 4690 OS and FlexOS)
 Concurrent DOS 386 1.0, 1.1, 2.0, 3.0 (BDOS 5.0-6.2)
 Concurrent DOS 386/MGE (Concurrent DOS 386 variant with advanced graphics terminal capabilities)
 Multiuser DOS 5.0, 5.01, 5.1 (BDOS 6.3-6.6) (successor of Concurrent DOS 386)
 CCI Multiuser DOS 5.0-7.22 (up to BDOS 6.6)
 Datapac Multiuser DOS
 Datapac System Manager 7 (derivative of Datapac Multiuser DOS)
 IMS Multiuser DOS 5.1, 7.0, 7.1 (BDOS 6.6-6.7)
 IMS REAL/32 7.50, 7.51, 7.52, 7.53, 7.54, 7.60, 7.61, 7.62, 7.63, 7.70, 7.71, 7.72, 7.73, 7.74, 7.80, 7.81, 7.82, 7.83, 7.90, 7.91, 7.92, 7.93, 7.94, 7.95 (BDOS 6.8 and higher) (derivative of Multiuser DOS)
 IMS REAL/NG (successor of REAL/32)
 Concurrent DOS XM 5.0, 5.2, 6.0, 6.2 (BDOS 5.0-6.2) (real-mode variant of Concurrent DOS with EEMS support)
 DR DOS 3.31, 3.32, 3.33, 3.34, 3.35, 5.0, 6.0 (BDOS 6.0-7.1) single-user, single-tasking native DOS derived from Concurrent DOS 6.0)
 Novell PalmDOS 1 (BDOS 7.0)
 Novell DR DOS "StarTrek"
 Novell DOS 7 (single-user, multi-tasking system derived from DR DOS, BDOS 7.2)
 Novell DOS 7 updates 1-10 (BDOS 7.2)
 Caldera OpenDOS 7.01 (BDOS 7.2)
 Enhanced DR-DOS 7.01.0x (BDOS 7.2)
 Dell Real Mode Kernel (DRMK)
 Novell DOS 7 updates 11-15.2 (BDOS 7.2)
 Caldera DR-DOS 7.02-7.03 (BDOS 7.3)
 DR-DOS "WinBolt"
 OEM DR-DOS 7.04-7.05 (BDOS 7.3)
 OEM DR-DOS 7.06 (PQDOS)
 OEM DR-DOS 7.07 (BDOS 7.4/7.7)
 FreeDOS (open source DOS variant)
 ProDOS (operating system for the Apple II series computers)
 PTS-DOS (DOS variant by Russian company Phystechsoft)
 TurboDOS (Software 2000, Inc.) for Z80 and Intel 8086 processor-based systems
 Multi-tasking user interfaces and environments for DOS
 DESQview + QEMM 386 multi-tasking user interface for DOS
 DESQView/X (X-windowing GUI for DOS)

Verkkokäyttöjärjestelmät

 Banyan VINES (Banyan Systems)
 Cambridge Ring
 Cisco IOS by Cisco Systems
 CSIRONET by (CSIRO)
 CTOS (Convergent Technologies, later acquired by Unisys)
 Data ONTAP by NetApp
 Enterprise OS by McDATA
 ExtremeWare by Extreme Networks
 ExtremeXOS by Extreme Networks
 Fabric OS by Brocade
 JunOS by Juniper
 NetWare (networking OS by Novell)
 NOS (developed by CDC for use in their Cyber line of supercomputers)
 Novell Open Enterprise Server (Open Source networking OS by Novell. Can incorporate either SUSE Linux or Novell NetWare as its kernel).
 Plan 9 (distributed OS developed at Bell Labs, based on Unix design principles but not functionally identical)
 Inferno (distributed OS derived from Plan 9, originally from Bell Labs)
 Plan B (distributed OS derived from Plan 9 and Off++ microkernel)
 SAN-OS by Cisco (now NX-OS)
 TurboDOS (Software 2000, Inc.)

Generic, commodity, and other
 BLIS/COBOL
 Bluebottle also known as AOS (a concurrent and active object update to the Oberon operating system)
 BS1000 by Siemens AG
 BS2000 by Siemens AG, now BS2000/OSD from Fujitsu-Siemens Computers (formerly Siemens Nixdorf Informationssysteme)
 BS3000 by Siemens AG (functionally similar to OS-IV and MSP from Fujitsu)
 FLEX9 (by TSC for Motorola 6809 based machines; successor to FLEX, which was for Motorola 6800 CPUs)
 GEM (windowing GUI for CP/M, DOS, and Atari TOS)
 GEOS (popular windowing GUI for PC, Commodore, Apple computers)
 JavaOS
 JNode (Java New Operating System Design Effort), written 99% in Java (native compiled), provides own JVM and JIT compiler. Based on GNU Classpath."JNode 0.2.8 Released", Thom Holwerda, OSNews, 4 February 2009.Jnode: Java New Operating System Design Effort , jnode.org. Retrieved 24 July 2014.
 JX Java operating system that focuses on a flexible and robust operating system architecture developed as an open source system by the University of Erlangen.
 KERNAL (default OS on Commodore 64)
 MERLIN for the Corvus Concept
 MorphOS (Amiga compatible)
 MSP by Fujitsu (successor to OS-IV), now MSP/EX, also known as Extended System Architecture (EXA), for 31-bit mode
 NetWare (networking OS by Novell)
 Oberon (operating system) (developed at ETH-Zürich by Niklaus Wirth et al.) for the Ceres and Chameleon workstation projects
 OSD/XC by Fujitsu-Siemens (BS2000 ported to an emulation on a Sun SPARC platform)
 OS-IV by Fujitsu (based on early versions of IBM's MVS)
 Pick (often licensed and renamed)
 PRIMOS by Prime Computer (sometimes spelled PR1MOS and PR1ME)
 Sinclair QDOS (multitasking for the Sinclair QL computer)
 SSB-DOS (by TSC for Smoke Signal Broadcasting; a variant of FLEX in most respects)
 SymbOS (GUI based multitasking operating system for Z80 computers)
 Symobi (GUI based modern micro-kernel OS for x86, ARM and PowerPC processors, developed by Miray Software; used and developed further at Technical University of Munich)
 TripOS, 1978
 TurboDOS (Software 2000, Inc.)
 UCSD p-System (portable complete programming environment/operating system/virtual machine developed by a long running student project at UCSD; directed by Prof Kenneth Bowles; written in Pascal)
 VOS by Stratus Technologies with strong influence from Multics
 VOS3 by Hitachi for its IBM-compatible mainframes, based on IBM's MVS
 VM2000 by Siemens AG
 Visi On (first GUI for early PC machines; not commercially successful)
 VPS/VM (IBM based, main operating system at Boston University for over 10 years.)

For Elektronika BK
 ANDOS
 CSI-DOS
 KMON
 MK-DOS

Harrastepohjaiset
 AROS (AROS Research Operating System, formerly known as Amiga Research Operating System)
 AtheOS (branched to become Syllable Desktop)
 Syllable Desktop (a modern, independently originated OS; see AtheOS)
 BareMetal
 DexOS – 32-bit operating system written in x86 assembly
 DSPnano RTOS
 EmuTOS
 EROS (Extremely Reliable Operating System)
 HelenOS, based on a preemptible microkernel design
 LSE/OS
 MenuetOS (extremely compact OS with GUI, written entirely in FASM assembly language)
 KolibriOS (a fork of MenuetOS)
 S-OS (a minimal DOS for Z80 machines)

Sulautetut

Kämmentietokoneet (PDA)
 DIP DOS on Atari Portfolio
 Embedded Linux
 Android
 Firefox OS
 Ångström distribution
 Familiar Linux
 Mæmo based on Debian deployed on Nokia's Nokia 770, N800 and N810 Internet Tablets.
 MeeGo merger of Moblin and Maemo
 OpenZaurus
 webOS from Palm, Inc., later Hewlett-Packard via acquisition, and most recently at LG Electronics through acquisition from Hewlett-Packard
 Inferno (hajautettu käyttöjärjestelmä Bell Labsilta)
 iOS
 Magic Cap
 MS-DOS on Poqet PC, HP 95LX, HP 100LX, HP 200LX, HP 1000CX, HP OmniGo 700LX
 NetBSD
 Newton OS on Apple MessagePad
 Palm OS from Palm, Inc; now spun off as PalmSource
 PEN/GEOS on HP OmniGo 100 and 120
 PenPoint OS
 Plan 9 from Bell Labs
 PVOS
 Symbian OS
 EPOC
 Windows CE, from Microsoft
 Pocket PC from Microsoft, a variant of Windows CE
 Windows Mobile from Microsoft, a variant of Windows CE
 Windows Phone from Microsoft

Mediasoittimet
 DSPnano RTOS
 iOS
 iPod software
 ipodlinux
 iriver clix OS
 RockBox

Mobiililaitteet ja älypuhelimet 

 BlackBerry OS
 Embedded Linux
 Access Linux Platform
 Android
 bada
 Firefox OS (projektinimi: Boot to Gecko)
 Openmoko Linux
 OPhone
 MeeGo (Maemon ja Moblinin yhdistymisestä)
 Mobilinux
 MotoMagx
 Qt Extended
 Sailfish OS
 Tizen (aiemmin nimellä LiMo Platform)
 Ubuntu Touch
 webOS
 PEN/GEOS, GEOS-SC, GEOS-SE
 iOS
 Palm OS
 Symbian platform (seuraaja Symbian OS:lle)
 Windows Mobile (korvaaja: Windows Phone)
 BlackBerry 10

Reitittimet
 AlliedWare, Allied Telesis (eli Allied Telesyn)
 AirOS, Ubiquiti Networks
 CatOS, Cisco Systems
 Cisco IOS (alkujaan Internetwork Operating System), Cisco Systems
 DD-WRT, NewMedia-NET
 Inferno (hajautettu käyttöjärjestelmä Bell Labsilta)
 IOS-XR, Cisco Systems
 IronWare, Foundry Networks
 JunOS, Juniper Networks
 LibreWRT;  GNU/Linux-libre
 OpenWrt
 RouterOS, Mikrotik
 ScreenOS, Juniper Networks, alkujaan Netscreeniltä
 Timos, Alcatel-Lucent
 FTOS, Force10 Networks
 RTOS, Force10 Networks
 Luettelo langattomien reittimien firmware-projekteista

Muut sulautetut
 Contiki
 ERIKA Enterprise
 eCos
 NetBSD
 uClinux
 MINIX
 NCOS
 freeRTOS, openRTOS and safeRTOS
 OpenEmbedded (or Yocto Project)
 pSOS (Portable Software On Silicon)
 QNX Unix-like real-time operating system, aimed primarily at the embedded systems market.http://www.qnx.com/
 REX OS (microkernel OS; usually an embedded cell phone OS)
 RIOT
 ROM-DOS
 TinyOS
 ThreadX
 DSPnano RTOS
 Windows Embedded
 Windows CE
 Windows Embedded Standard
 Windows Embedded Enterprise
 Windows Embedded POSReady
 Wind River VxWorks Small footprint, scalable, high-performance RTOS for embedded microprocessor based systems.
 Wombat OS (microkernel OS; usually a real time embedded OS)

LEGO Mindstorms
 brickOS
 leJOS

Capability-based
 Cambridge CAP computer operating system demonstrated the use of security capabilities, both in hardware and software, also a useful fileserver, implemented in ALGOL 68C
 Flex machine – Custom microprogrammable hardware, with an operating system, (modular) compiler, editor, * garbage collector and filing system all written in ALGOL 68.
 HYDRA – Carnegie Mellon -yliopiston C.mmp-tietokoneelle, toteutettu BLISS-ohjelmointikielellä
 KeyKOS nanokernel
 EROS microkernel
 CapROS EROS successor
 Coyotos EROS successor, goal: be first formally verified OS
 V from Stanford, early 1980s

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