Comparison of real-time operating systems: Difference between revisions

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{{Short description|none}}

This is a list of [[real-time operating system]]s. An RTOS is an [[operating system]] in which the time taken to process an input stimulus is less than the time lapsed until the next input stimulus of the same type.

{{More citations needed|date=June 2024}}

This is a list of [[real-time operating system]]s (RTOSs). This is an [[operating system]] in which the time taken to process an input stimulus is less than the time lapsed until the next input stimulus of the same type.

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Please:

Please add citations for any RTOS that does not have its own article.

Add citations for any RTOS that lacks its own article.

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Keep table entries brief.

In each table, for each term, link one instance only, usually the 1st, remove other WP:OVERLINK(s).

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{{mw-datatable}}

{| class="wikitable sortable"

{| class="wikitable sortable mw-datatable"

! Name !! License !! Source&nbsp;model || Target uses !! Status !! Platforms !! Official&nbsp;website

! Name !! [[Software license|License]] !! [[Source code|Source]]&nbsp;model || Target uses !! Status !! Platforms

|-

| Abassi[[Apache Mynewt]]|| {{proprietaryfree|[[Apache License 2.0|Apache 2.0]]}} || closed| open source || embedded || active || [[AVR32]], [[Atmel AVR|ATmega]], [[Freescale ColdFire|ColdFire]], [[ARM Cortex-A9|Cortex-A9M]], [[ARMMIPS Cortex-M0architecture|Cortex-M0MIPS32]], [[ARMPIC Cortex-M3|Cortex-M3]],microcontroller#PIC32M [[ARM CortexMIPS-M4|Cortex-M4]],based [[TI MSP430line|MSP430]],Microchip [[PIC32]], TMS320C2000, 80251, [[8051RISC-V]] || {{URL|www.code-time.com/products.html}}

|-

| [[BeRTOS]]|| {{free|[[GNU General Public License|Modified GNU GPL]]}} || open source || embedded || archived || ARM, Cortex-M3, ARM ARM7TDMI, Atmel AVR, PowerPC (emu), x86 (emu), x86-64 (emu)

| AMOS || {{proprietary}} || {{dunno}} || commercial || closed || [[Motorola 68000 series|680x0]], 683xx, [[x86]] via emulation || {{URL|www.alphamicro.com}}

|-

| [[ChibiOS/RT]] || {{free|Dual, [[GNU General Public License|GNU GPL]] or proprietary}} || open source || embedded, small [[Memory footprint|footprint]]

| AMX RTOS || {{proprietary}} || closed || embedded || active || 680x0, 683xx, ARM, ColdFire, [[MIPS architecture|MIPS32]], [[PowerPC]] || {{URL|www.kadak.com/rtos/rtos.htm}}

|active|| x86, [[ARM7]], [[ARM Cortex-A9|ARM9]], Cortex-M0-M3-M4, [[PowerPC e200]]z, STM8, STM32, AVR, MSP430, ColdFire, [[H8S]]

|-

| [[ChorusOS]] || {{dunno}} || {{dunno}} || {{dunno}} || defunct || [[SPARC]], x86, PowerPC

| [[Apache Mynewt]] || {{free|[[Apache License 2.0|Apache 2.0]]}} || open || embedded || active || [[ARM Cortex-M]], [[MIPS_architecture|MIPS32]], [[PIC_microcontroller#PIC32M_MIPS-based_line|Microchip PIC32]], [[RISC-V]] || {{URL|mynewt.apache.org}}

|-

| [[mbed|Arm Mbed OSContiki]] || {{Freefree|[[ApacheBSD License 2.0licenses|Apache 2.0BSD]]}} || open source || embedded, [[wireless sensor network|WSN]] || active || Cortex-MMSP430, Cortex-RAVR, Cortex-AARM ||{{URL|os.mbed.com}}

|-

| [[Data General RDOS]] || {{proprietary}} || {{dunno}} || general purpose || defunct || [[Data General Nova]], [[Data General Eclipse]]

| uKOS || {{free|[[GNU General Public License|GNU GPL]]}} || open source || embedded || active || Cortex-M3-M4-M7-H7, 6833x, PIC, [[Swiss Center for Electronics and Microtechnology|CSEM]] icyflex-1, [[STM32]] || {{URL|www.ukos.ch}}

|-

| ARTOS (Locamation)[[Deos]] || {{proprietary}} || closed || [[power-systemsafety automation]]critical || rowspan="2" | active || x86, ||PowerPC, ARM, MIPS {{URL|www.locamation.com/}}

|-

| ARTOS (Robotu)[[DioneOS]] || {{proprietary}} || {{dunno}}available || embedded,for robotslicensee || defunctembedded || ARM9+MSP430, ||MSP430x {{URL|www.robotu.com/ARTOS/Welcome.html}}

|-

| [[DNIX]] || {{proprietary}} || closed || general purpose || defunct || 68000

| Atomthreads || {{free|[[BSD licenses|BSD]]}} || open source || embedded || active || [[Atmel AVR|AVR]], STM8, [[ARM architecture|ARM]], MIPS || {{URL|atomthreads.com}}

|-

| [[GEC Computers|GEC]] DOS || {{proprietary}} || closed || process control || defunct || GEC 4000 series

| AVIX || {{proprietary}} || closed || embedded || active || Atmel AT91SAM3(U/S), [[EFM32]], NXP [[NXP LPC|LPC1300-1700]], ST Micro STM32, Texas Instruments LM3S, Toshiba TMPM330, Microchip PIC32MX-PIC24F-PIC24H-dsPIC30F-dsPIC33F || {{URL|www.avix-rt.com}}

|-

| [[DSOS]] || {{proprietary}} || closed || {{dunno}} || defunct || [[Texas Instruments|TI]]-980A minicomputer

| [[BeRTOS]] || {{free|[[GNU General Public License|modified GNU GPL]]}} || open source || embedded || active || ARM, Cortex-M3, ARM ARM7TDMI, Atmel AVR, PowerPC (emu), x86 (emu), x86-64 (emu) || {{URL|www.bertos.org}}

|-

| [[DSP/BIOS]] || {{proprietary}} || closed, available with license|| general purpose || maintenance only || Mostly Texas Instruments C2800, C5500, C6000 and OMAP DSP cores. Replaced by [[TI-RTOS]], but available for download.

| BOOS Core || {{free|[[GNU General Public License|GNU GPL]]}} || open source || embedded || active || ARMv5TEJ (TI AM18x), DSP (TI TMS320C64x) || {{URL|www.baigudin.software/boos/}}

|-

| [[eCos]] || {{free|[[GNU General Public License|Modified GNU GPL]]}} || open source

| BRTOS || {{free|[[MIT License|MIT]]}} || open source || embedded || active || Freescale Kinetis (ARM Cortex-M4), Freescale Coldfire V1, Freescale HCS08, ST STM32F4xx (ARM Cortex-M4F), NXP LPC11xx (ARM Cortex-M0), NXP LPC176x (ARM Cortex-M3), Renesas RX600 (RX62N), Texas Instruments MSP430, Texas Instruments Stellaris LM3S8968 (ARM Cortex-M3), Texas Instruments Stellaris LM4F120H5QR (ARM Cortex-M4F), Atmel ATMEGA328/128 and Microchip PIC18 || {{URL|https://github.com/brtos/brtos}}

| rowspan="2" |embedded|| inactive || ARM-XScale-Cortex-M, CalmRISC, 680x0-ColdFire, fr30, FR-V, H8, IA-32, MIPS, MN10300, [[OpenRISC]], PowerPC, SPARC, [[SuperH]], V8xx

|-

| [[CapROSeCosPro]] || {{free|[[GNU General Public License|Modified GNU GPL]] or [http://www.ecoscentric.com/ecospro-license.shtml eCosPro license]}} || open source ||with embeddednon-free portions || active || ARM7-9, Cortex-A5-A9-M3-M4-M7, 680x0-ColdFire, H8-H8S, IA-32, ARM9MIPS32, ||MIPS64, microMIPS, NIOS II, OpenRISC, PowerPC, SPARC, SH4/4A, TILE-Gx, XScale {{URL|www.capros.org}}

|-

| [[Segger Microcontroller Systems|embOS]] || {{proprietary}} || closed, available to customers, free object code for non-commercial use || embedded, industrial, IoT, safety critical || rowspan="2" | active || ARM7/9/11, ARM Cortex-A/R/M, AVR, AVR32, C16x, CR16C, ColdFire, H8, HCS12, M16C, M32C, MSP430, NIOS2, PIC18/24/32, R32C, R8C, RISC-V, RL78, RH850, RX100/200/600/700, RZ, SH2A, STM8, ST7, V850, 78K0, 8051

| [[ChibiOS/RT]] || {{partial|Mixed, [[GNU General Public License|GNU GPL]] or proprietary}} || open source || embedded, small [[Memory footprint|footprint]] || active || x86, [[ARM7]], ARM9, Cortex-M0-M3-M4, [[PowerPC e200]]z, STM8, STM32, AVR, MSP430, ColdFire, [[H8S]]|| {{URL|www.chibios.org/dokuwiki/doku.php}}, {{URL|sourceforge.net/projects/chibios}}

|-

| [[ERIKA Enterprise]]|| {{free|[[GPL]] and [[GPL linking exception]]}} || open source || embedded || ARM7, ARM Cortex-M, ARM Cortex-A (on Jailhouse hypervisor), Hitachi H8, Altera Nios2, Microchip dsPIC (including dsPIC30, dsPIC33, and PIC24), Microchip PIC32, ST Microelectronics ST10, Infineon C167, Infineon Tricore, [[Freescale]] PPC e200 (MPC 56xx) (including PPC e200 z0, z6, z7), Freescale S12XS, EnSilica eSi-RISC, AVR, Lattice Mico32, MSP430, [[Renesas Electronics|Renesas]] RX200, x86-64 (on Jailhouse hypervisor)

| [[ChorusOS]] || {{dunno}} || {{dunno}} || {{dunno}} || defunct || [[SPARC]], x86, PowerPC || {{URL|docs.sun.com/app/docs/prod/chorus5}}

|-

| ChronOS[[Extremely Reliable Operating System|EROS]]|| {{free|[[GNU General Public License|Modified GNU GPL]]}} || open source || research,experimental<br general/>research purposeuse || activedormant || x86,IA-32 ARM || {{URL|chronoslinux.org}}

|-

| [[FlexOS]] || {{proprietary}} || closed || general purpose, industrial, POS || defunct || 186, 286, 386, V60, V70, 68000

| CoActionOS (now Stratify OS) || {{free|[[GNU General Public License|Modified GNU GPL]] or proprietary}} || open source || embedded || discontinued || ARM Cortex-M3, LPC17xx || {{URL|www.coactionos.com}}

|-

| [[FreeRTOS]] || {{free|[[MIT License|MIT]]}}

| cocoOS || {{free|[[BSD licenses|BSD]]}} || open source || embedded || active || AVR, MSP430, STM32 || {{URL|www.cocoos.net}}

| rowspan="2" |open source

| embedded

| rowspan="5" |active|| ARM, AVR, AVR32, ColdFire, ESP32, HCS12, IA-32, Cortex-M3-M4-M7, [[Infineon XMC4000]], MicroBlaze, MSP430, PIC, PIC32, Renesas H8/S, [[RISC-V]], RX100-200-600-700, 8052, STM32, [[TriCore]], [[EFM32]]

|-

| [[Fuchsia (operating system)|Fuchsia]] || {{partial|Varies}} || embedded ||[[AArch64]], [[x86-64]]

| Concurrent CP/M,<br />became [[MP/M]] || {{proprietary}} || closed (meanwhile: open source) || general purpose, industrial || historic || 8080, Z80, 8086 || Digital Research

|-

| [[Keil (company)|Keil RTX]] || {{free|[[Apache License 2.0|Apache 2.0]]}} || open source || embedded || Arm Cortex-M

| Concurrent DOS,<br />became [[Multiuser DOS]] || {{proprietary}} || closed || general purpose, industrial || defunct || 8086, 286, 386, 68000, (also 8080/Z80 in dual-processor variants) || Digital Research

|-

| [[Contiki]]FunkOS || {{free|[[BSDSleepycat licensesLicense|BSDModified Sleepycat License]]}} || open source || embedded, [[wireless sensor network|WSN]] || active ||AVR, MSP430, AVR, ARM || {{URL|www.contikiCortex-os.org}}M3

|-

| COS[[HeartOS]] || {{proprietary}} || closed || [[processsafety control]]critical || defunctx86, ||PowerPC, [[GECARM 4000 series]] || {{dunno}}

|-

| Huawei [[LiteOS]]|| {{free|[[BSD licenses|BSD]]}} || open source || embedded || defunct || ARM (M0/3/4/7, A7/17/53, ARM9/11), x86, RISC-V

|-

| [[HarmonyOS]] ||{{proprietary}} || closed || embedded || active ||[[AArch64]], [[x86-64]], [[RISC-V]], LingxiISA

| CooCox CoOS || {{free|[[BSD licenses|BSD]]}} || open source || general purpose || active || STM32, NXP LPC1000, TI LM3S8962, Nuvoton NU1xx,Holtek HT32|| {{URL|www.coocox.org/CoOS.htm}}

|-

| [[DeosIBM 4680 OS]] || {{proprietary}} || closedrowspan="4" || safety criticalclosed || activerowspan="2" || x86general purpose, PowerPCindustrial, MIPSPOS || {{URLdefunct |www.ddci.com/products_deos.php}}| 286

|-

| [[DioneOSIBM 4690 OS]] || {{proprietary}} || availablerowspan="7" for licensee || embedded || active || MSP430286, MSP430x386 || {{URL|www.elesoftrom.com.pl/en/os}}

|-

| [[Integrity (operating system)|INTEGRITY]] || {{proprietary}} || rowspan="2" | embedded || ARM, [[XScale]], [[Blackfin]], ColdFire, MIPS, PowerPC, x86

| distortos || {{free|[[Mozilla Public License|Mozilla]]}} || open source || embedded || active || [[ARMv6-M]] architecture ([[ARM Cortex-M#Cortex-M0|ARM Cortex-M0]], [[ARM Cortex-M#Cortex-M0+|ARM Cortex-M0+]], [[ARM Cortex-M#Cortex-M1|ARM Cortex-M1]]): [[STM32#STM32 F0|STM32F0]], [[STM32#STM32 L0|STM32L0]]; [[ARMv7-M]] architecture ([[ARM Cortex-M#Cortex-M3|ARM Cortex-M3]], [[ARM Cortex-M#Cortex-M4|ARM Cortex-M4(F)]], [[ARM Cortex-M#Cortex-M7|ARM Cortex-M7(F)]]): [[STM32#STM32 F1|STM32F1]], [[STM32#STM32 F4|STM32F4]], [[STM32#STM32 F7|STM32F7]], [[STM32#STM32 L4|STM32L4]] || {{URL|distortos.org}}

|-

| [[DNIXINtime]] || {{proprietary}} || closedx86 || general purpose || defunct || 68000 || {{dunno}}

|-

| dnx RTOS[[ITRON]] || {{free|[[GNU GPL]], modified GPL, [[BSD licenses|BSDT-License]]}} || open sourcevaries || embedded ([[Unix-like]]) || active || ARM, Cortex-M3MIPS, STM32x86, ||[[Renesas]] {{URL|www.dnxRX100-rtos.org}}200-600-700-others

|-

| [[GEC:ru:Kaspersky ComputersOS|GECKaspersky OS]] DOS || {{proprietary}} || closedrowspan="2" || process controlopen source|| defunctsafety critical, virtualization || GECx86, 4000x86_64, seriesARMV5, ||ARMV7, {{dunno}}ARMV8, MIPS32

|-

| [[KolibriOS]] || {{free|[[GNU General Public License|GNU GPL]]}} || embeddable || x86

| [[DSOS]] || {{dunno}} || {{dunno}} || {{dunno}} || defunct || [[Texas Instruments|TI]]-980A minicomputer || {{dunno}}

|-

| [[LynxOS]] || {{proprietary}} || source available || embedded ||[[Motorola 68010]], x86/IA-32, ARM, Freescale PowerPC, [[PowerPC 970]], LEON

| [[DSP/BIOS]] || {{free}} || closed, available with license|| general purpose || maintenance only || Mostly Texas Instruments C2800, C5500, C6000 and OMAP DSP cores. Replaced by [[TI-RTOS]], but available for download. || {{URL|www.ti.com/tool/dspbios}}

|-

| [[Mbed|Mbed OS]] || {{free|[[Apache License 2.0|Apache 2.0]]}} || open source || embedded || abandoned <ref name="abandoned">{{Cite web |title=Important Update on Mbed |url=https://os.mbed.com/blog/entry/Important-Update-on-Mbed/ |access-date=2024-07-16 |language=en}}</ref> || Arm Cortex-M

| [[DSPnano RTOS]] || {{partial|Mixed, open source and commercial}} || open source || MCU, DSC, DSP SoC || active || R8C, M16C, PIC24, dsPIC33 || {{URL|www.rowebots.com/products/dspnano}}

|-

| DuinOS[[MenuetOS]] || {{free|[[GNU General Public License|Modified GNU GPL]]}} || open source || general purposeactive || active{{dunno}} || AVRIA-32 (Arduino) || {{URL|code.google.com/p/duinos}}

|-

| [[Multi-Environment Real-Time|MERT]] || {{proprietary}}(Bell Labs) || closed || OS for long-distance telephone switching systems || inactive || [[PDP-11]]

|eChronos

|AGPLv3

|open source

|embedded

|active

|ARM Cortex-M3 - M7

|https://ts.data61.csiro.au/projects/TS/echronos/

|-

| [[eCosMicro-Controller Operating Systems|MicroC/OS-III]] || {{free|[[GNU General PublicApache License 2.0|ModifiedApache GNU GPL2.0]]}} || open source || embedded || active || ARMARM7-XScale9-11/Cortex-MM1-3-4-A8/9, CalmRISCAVR, HC11/12/S12, 680x0-ColdFire, fr30Blackfin, FR-VMicroBlaze, H8NIOS, IA-328051, x86, Win32, H8S, M16C, M32C, MIPS, MN1030068000, OpenRISCPIC24/dsPIC33/PIC32, MSP430, PowerPC, SPARCSH, StarCore, [[SuperHRenesas]] RX100-200-600-700, V8xxRL; ||STM32, {{URL|ecos.sourceware.org}}.

|-

| [[eCosProMontaVista Linux]] || {{free|[[GNU General Public License|Modified GNU GPL]] or [http://www.ecoscentric.com/ecospro-license.shtml eCosPro license]}} || open source with non-free portions || embedded || active || ARM7-9, Cortex-A5-A9-M3-M4-M7, 680x0-ColdFire, H8-H8S, IA-32, MIPS32, MIPS64, microMIPS, NIOS II, OpenRISC, PowerPC, SPARC, SH4/4A, TILE-Gx, XScale || {{URL|www.ecoscentric.com/ecos/ecospro.shtmldunno}} ||

|-

| [[MP/M]] || {{proprietary}} || closed (meanwhile: open source) || general purpose, industrial || defunct || 8080, Z80, 8086

| [[Segger Microcontroller Systems|embOS]] || {{proprietary}} || closed, available to customers, free for non-commercial use || embedded, industrial, IoT, safety critical || active || ARM7/9/11, ARM Cortex-A/R/M, AVR, AVR32, C16x, CR16C, ColdFire, H8, HCS12, M16C, M32C, MSP430, NIOS2, PIC18/24/32, R32C, R8C, RISC-V, RL78, RH850, RX100/200/600/700, RZ, SH2A, STM8, ST7, V850, 78K0, 8051 || {{URL|www.segger.com/embos.html}}

|-

| Embox[[MQX]] || {{free|[[BSD licenses|BSD]]proprietary}} || opencomplimentary source available || embedded || active || [[ARMFreescale architecture|ARM]]Power, [[LEON]]ColdFire, [[MicroBlaze]],Kinetis [[MIPSCortex architecture|MIPS]]ARM, [[PowerPC]],List [[x86of Freescale products]] || {{URL|github.com/embox/embox}}

|-

| [[Multiuser DOS]] || {{proprietary}} || closed || general-purpose, industrial || defunct || 386

| Embkernel || {{free|[[GNU Lesser General Public License|GNU LGPL]]}} || open source || embedded || active || ARM Cortex M || {{URL|sourceforge.net/p/embkernel}}

|-

| [[Nano-RK]] || {{free|Dual, GPL or commercial}} || open source || embedded, [[wireless sensor network|WSN]] || defunct || AVR, MSP430

| [[ERIKA Enterprise]] || {{free|[[GPL]] and [[GPL linking exception]]}} || open source || embedded || active || ARM7, ARM Cortex-M, ARM Cortex-A (on Jailhouse hypervisor), Hitachi H8, Altera Nios2, Microchip dsPIC (including dsPIC30, dsPIC33, and PIC24), Microchip PIC32, ST Microelectronics ST10, Infineon C167, Infineon Tricore, [[Freescale]] PPC e200 (MPC 56xx) (including PPC e200 z0, z6, z7), Freescale S12XS, EnSilica eSi-RISC, AVR, Lattice Mico32, MSP430, [[Renesas Electronics|Renesas]] RX200, x86-64 (on Jailhouse hypervisor) || {{URL|http://www.erika-enterprise.com}}

|-

| EUROS[[QNX|Neutrino]] || {{proprietary}} || closedsome source provided || microkernel, embedded, industrial || rowspan="6" | active || 8/16/32 bit processors: among others AVRARM, 8051ARM64, XC800MIPS, 16FXPPC, XC166SH, ARMx86, Cortexx86-M364, PowerPC,XScale Nios II, MIPS32, PIC32 || {{URL|www.euros-embedded.com}}

|-

| [[Nucleus RTOS]] || {{proprietary}} || source provided

| [[Extremely Reliable Operating System|EROS]] || {{free|[[GNU General Public License|Modified GNU GPL]]}} || open source || experimental<br/>research use || dormant || IA-32 || {{URL|www.eros-os.org}}

|embedded|| ARM (Cortex-M3-M4-R4-R4F-A8-A9, ARM7-9-11), PowerPC, MIPS32-16e, microMIPS, ColdFire, SuperH

|-

| [[Network UPS Tools|NUT]] || {{proprietary}}

| F9 microkernel || {{free|Modified [[BSD licenses|BSD]]}} || open source || embedded || maintenance || ARM Cortex-M3/M4 || {{URL|github.com/f9micro/f9-kernel}}

| rowspan="2" |open source|| embedded, industrial || ARM-M0, ARM-M0+, ARM Cortex-M3, ARM9, ARM Cortex-M7, Cortex-M3

|-

| [[Ethernut|Nut/OS]] || {{free|[[BSD licenses|BSD]]}} || embedded, industrial || AVR, AVR32, [[ARM7#ARM7TDMI .281993.29|ARM7]], [[ARM Cortex-A9|ARM9]], Cortex-M3

| Femto OS || {{free|[[GNU General Public License|GNU GPLv3]]}} || open source || embedded || active || AVR || {{URL|www.femtoos.org}}

|-

| [[NuttX]] || {{free|[[Apache License 2.0|Apache 2.0]]}} || open source || embedded, small footprint || Linux user mode, ARM7-9, Cortex-A5-A8-A9-M0-M3-M4-M7, [[8052]], [[Espressif]] [[ESP32]], [[LatticeMico32|Lattice LM32]], Renesas MC16C/26/SH-1, [[RISC-V]], Zilog Z16F, Zilog eZ80 Acclaim!, Zilog Z8Encore!, [[Z80]], MIPS PIC32MX, PIC32MZ

| [[FlexOS]] || {{proprietary}} || closed || general purpose, industrial, POS || defunct || 186, 286, 386, V60, V70, 68000 || Digital Research, Novell

|-

| [[OpenComRTOS]] || {{proprietary}} || source provided || embedded || [[Freescale]] [[PowerPC]], [[Texas Instruments]] C66xxx [[Digital signal processor|DSP]], [[ARM architecture|ARM]], [[XMOS]], [[MicroBlaze]], [[LEON]], [[NXP Semiconductors|NXP]] CoolFlux [[Digital signal processor|DSP]], [[X-Fab|Melexis]] MLX16, [[Win32]], [[Linux]]

| FreeOSEK || {{free|[[GNU General Public License|GNU GPLv3]]}} || open source || embedded || active || Cortex-M4, MIPS, MSP430, SPARC LEON3 || {{URL|https://github.com/ciaa/Firmware}}

|-

| [[FreeRTOSOS2000]] || {{free|[[MIT License|MIT]]proprietary}} || open source{{dunno}} || embedded || active || ARM,[[MIPS AVR,architecture|MIPS]] AVR32,(Baget ColdFirevariant), HCS12, IA[[KOMDIV-32]], Cortex[[KOMDIV-M3-M4-M764]], MicroBlaze,[[Intel]] MSP430,[[board PIC,support PIC32, Renesas H8/S, RX100-200-600-700, 8052, STM32,package|BSP]]s ([[EFM32x86]]) || {{URL|www.freertos.org}}

|-

| [[OS4000]] || {{proprietary}} || closed || process control || maintenance only || GEC 4000 series

| Frosted || {{free|[[GNU General Public License|GNU GPL]]}} || open source || embedded, [[POSIX]] compliant, [[unix-like]] || active || ARM Cortex-M || {{URL|https://github.com/insane-adding-machines/frosted}}

|-

| [[Operating System Embedded|OSE]] || {{proprietary}} || available to customers || general purpose

|Fuchsia

| rowspan="3" |active|| ARM, PowerPC, x86, TI OMAP, ...

|Varies

|open source

|embedded

|active

|?

|[https://fuchsia.googlesource.com/ fuchsia.googlesource.com]

|-

| [[OS-9]] || {{proprietary}} || available to customers || rowspan="2" | embedded || ARM-strongARM, MIPS, PowerPC, SuperH, x86/Pentium, XSCALE, [[Motorola 6809]], 680x0, SPARC

| [[FunkOS]] || {{free|modified [[Sleepycat License]]}} || open source || embedded || active || AVR, MSP430, Cortex-M3|| {{URL|funkos.sourceforge.net}}

|-

| [[OSEK]] || {{free|Dual, GPL or commercial}} || specification || engine control units

| Fusion RTOS || {{free}} || {{dunno}} || semi-general purpose || active || ARM, Blackfin, StarCore, DSP 56800E || <!-- blacklisted www.unicoi.com/free_rtos.htm -->

|-

| [[Phoenix-RTOS]] || {{free|[[BSD licenses|BSD]]}} || open source || embedded

| FX-RTOS|| {{proprietary}} || source code provided || embedded || active || ARMv6-M (Cortex-M0/M1), ARMv7-M (Cortex-M3), ARMv7-A (including Cortex A9 MPCore), x86, AVR32, PIC32, MIPS M4K, TI MSP430 || {{URL|rtos.eremex.com/products}}, {{URL|fxrtos.ru}}

| rowspan="2" |active|| ARMv7 Cortex-M, ARMv7 Cortex-A, IA-32, RISC-V

|-

| [[HeartOSPikeOS]] || {{proprietary}} || closedavailable to customers || certifiable safety critical& ||security, embedded activevirtualisation || x86PPC, PowerPCx86, ARM, ||MIPS, SPARC-LEON, RISC-V {{URL|www.ddci.com/products_heartos.php}}

|-

| [[Helium (operating system)|HeliumProtothreads]] || {{free|[[GNUBSD Lesser General Public Licenselicenses|GNU LGPLBSD]]}} || open source || Embeddedgeneral ||purpose Active || HCS08, AVR || {{URL|helium.sourceforge.net}}

|active|| Architecture independent

|-

| [[HPpSOS (real-1000/RTEtime operating system)|pSOS]] || {{dunnoproprietary}} || {{dunno}} || {{dunno}} || {{dunno}}discontinued || {{dunno}}680x0 || {{URL|www.hp.com/products1/rte/tech_support/documentation}}

|-

| [[PX5 RTOS]] || {{proprietary}} || [[royalty-free]] licensing || embedded || rowspan="5" | active || Embedded MCU and MPU architectures. ARM's Cortex-M, Cortex-R, Cortex-A, RISC-V. AMP and SMP configurations.

| Hybridthreads || {{dunno}} || open source || FPGA || active || Xilinx Virtex-II Pro ML310, Xilinx Virtex-II Pro XUP || {{URL|hthreads.csce.uark.edu/wiki/About_Hthreads}}

|-

| [[QNX]] || {{proprietary}} || {{dunno}} || microkernel, embedded, industrial || active

| hyperCOS || {{dunno}} || free evaluation (not open source) || embedded || active || ARM7, ARM9, Cortex-R, Cortex-M3, Cortex-M4F || {{URL|socware.net}}

|-

| [[QP (framework)|QP]] || {{free|Dual, GPL or commercial}} || dual || MCU, DSC, DSP SoC || ARM7/9, ARM Cortex-M3-M0, MSP430, TMS320C28x, AVR, AVRXmega, ColdFire, 68HC08, M16C/R8C, H8, 8051, 80251, PIC18, PIC24/dsPIC33, Nios II, PSoC1

| [[IBM 4680 OS]] || {{proprietary}} || closed || general purpose, industrial, POS || defunct || 286 || IBM (DR Concurrent DOS 286 derivative)

|-

| [[IBM 4690 OSREAL/32]] || {{proprietary}} || closed || general -purpose, industrial, POS || active || 286, 386 || IBM (DR FlexOS 286/386 derivative)

|-

| [[Linux kernel#Scheduling|Real-time Linux]] ([[PREEMPT RT]]) || {{free|[[GNU General Public License|GNU GPLv2]]}} || open source || general purpose || x86, x86_64, RISC-V, ARM64 and LoongArch (ARM and POWER in the ''-rt'' branch)<ref>[https://wiki.linuxfoundation.org/realtime/preempt_rt_versions PREEMPT_RT patch versions]</ref>

| [[Integrity (operating system)|Integrity]] || {{proprietary}} || closed || embedded || active || ARM, [[XScale]], [[Blackfin]], ColdFire, MIPS, PowerPC, x86 || {{URL|www.ghs.com/products/rtos/integrity.html}}

|-

| [[INtimeREX OS]] || {{proprietary}} || closed, available with license || embeddedrowspan="4" || activeembedded || x86inactive || {{URL|www.tenasys.com/intime}}ARM

|-

|IntrOS [[RIOT (operating system)|RIOT]] || {{free|[[MITGNU Lesser General Public License|MITGNU LGPL]]}} || open source || embedded, small footprint || active || ARM7, ARM Cortex- M, STM8MSP430, AVR8AVR, ||RISC-V, {{URL|github.com/stateos/IntrOS}}Xtensa

|-

| [[RMX (operating system)|RMX]] || {{proprietary}} || closed || defunct || [[Intel 8080]], [[Intel 8086|8086]], [[Intel 80386|80386]], higher

| [[ITRON]], [[µITRON]] || {{partial|Varies}} || varies || embedded || active || ARM, MIPS, x86, [[Renesas]] RX100-200-600-700-others || {{URL|www.tron.org}}, {{URL|www.t-engine.org}}

|-

| [[Rodos (operating system)|RODOS]] || {{free|[[BSD licenses|BSD]]}} || source provided || active || [[ARM architecture|ARMv7]] (M3, A8, A9), [[AVR32]], [[PowerPC 400|PowerPC 405]], [[SPARC]]64

| ISIX || {{free|[[GNU Lesser General Public License|GNU LGPL]]}} || open source || embedded || active || Cortex-M3 || [http://bryndza.boff.pl/index.php?dz=rozne&id=isixrtos bryndza.boff.pl/index.php?dz=rozne&id=isixrtos]

Platforms: SmartFusion2, [[Raspberry Pi|RaspberryPi]], [[STM32]]

On an OS: [[Linux]], [[Microsoft Windows|Windows]], [[macOS]], [[FreeRTOS]], [[RTEMS]]

|-

| [[RSX-11]] || {{proprietary}} || {{dunno}} || {{dunno}} || historic || PDP-11

| iRTOS || {{free|[[GNU Lesser General Public License|GNU LGPL]]}} || open source || embedded || active || AVR, ARM7 || {{URL|irtos.sourceforge.net}}

|-

| [[KolibriOSRT-11]] || {{free|[[GNUproprietary}} General Public License|GNU| GPL]]{{dunno}} || opengeneral sourcepurpose || embeddabledefunct || activePDP-11 || x86 || {{URL|www.kolibrios.org}}

|-

| [[RTAI]] || {{free|[[GNU General Public License|GNU GPL]]}} || rowspan="3" | open source || general purpose || rowspan="2" | active || x86 (with and without FPU and TSC), x86-64, PowerPC, ARM (StrongARM; ARM7: clps711x-family, Cirrus Logic EP7xxx, CS89712, PXA25x), m68k (supporting both MMU and NOMMU cpus)

| Kithara RTS || {{proprietary}} || closed || general purpose, industrial || active || Windows extension, x86, x86-64, Windows XP-10 || {{URL|www.kithara.de}}

|-

| [[RTEMS]] || {{free|[[BSD licenses|BSD]]}} || embedded || AArch64, ARM, Blackfin, ColdFire, TI C3x/C4x, H8/300, x86, x86_64, 68k, Microblaze, [[Milkymist]] SoC, MIPS, Nios II, PowerPC, SuperH, SPARC, [[ERC32]], LEON, Mongoose-V

| Lepton || {{free|[[Mozilla Public License|Mozilla]]}} || open source || embeddable || active || ARM9 (ATMEL AT91SAM9261, AT91SAM9260), ARM7 (ATMEL AT91SAM7x, AT91SAM7SE, AT91M55800), CortexM3 (ST STM32F103, Texas Instrument Stellaris) et CortexM4 (Freescale Kinetis) || {{URL|github.com/lepton-distribution/lepton}}

|-

| [[RTLinux]] || {{free|[[GNU General Public License|GNU GPL]]}} || general purpose || inactive || same as [[Linux]]

| LithOS || {{proprietary}} || {{dunno}} || embedded, industrial || active || LEON2-3-4, x86 || {{URL|www.fentiss.com}}, {{URL|www.xtratum.org}}

|-

| [[RT-Thread]] || {{free|[[Apache License 2.0|Apache 2.0]]}} || open source || embedded

| [[LynxOS]] || {{proprietary}} || source code available || embedded || active || [[Motorola 68010]], x86/IA-32, ARM, Freescale PowerPC, [[PowerPC 970]], LEON || {{URL|www.lynuxworks.com/rtos}}

| rowspan="3" |active|| ARM, ARM Cortex-M0-M3-R4-M4-M7, IA-32, AVR32, Blackfin, nios, PPC, M16C, MIPS (loongson-1b-1c, PIC32，xburst), MicroBlaze, V850, unicore32,

|-

| [[RTXC Quadros]] || {{proprietary}} || source available || embedded || ARM - Atmel/Freescale/NXP/[[STM32|ST]]/TI, [[Blackfin]], 680x0-ColdFire, PowerPC, StarCore, TI-Luminary Stellaris, TI OMAP, XScale

| Mark3 || {{free|[[BSD licenses|BSD]]}} || open source || embedded || active, beta || {{dunno}} || {{URL|www.mark3os.com}}

|-

| [[RTX (operating system)|RTX, RTX64]] || {{proprietary}} || closed || MS Windows extension || x86, x86-64

| MaRTE OS || {{free|[[GNU General Public License|GNU GPL]]}} || open source || embedded || active || IA-32 || {{URL|marte.unican.es}}

|-

| MAX II,IV[[RX116]] || {{proprietarydunno}} || {{dunno}} || {{dunno}}embedded, industrial || {{dunno}}rowspan="3" | defunct || [[MODCOMPNEC V20]], II[[NEC V30]], IV[[NEC V40]], ...[[NEC ||V50]] {{dunno}}

|-

| [[RX616]] || {{dunno}} || {{dunno}} || safety critical, embedded, industrial ||[[NEC V60]], [[NEC V70]]

| [[MenuetOS]] || {{free|[[GNU General Public License|GNU GPL]]}} || open source || {{dunno}} || active || IA-32 || {{URL|www.menuetos.net}}

|-

| Menuet 64[[RX-UX832]] || {{proprietarydunno}} || unknown || {{dunno}} || activeembedded, || IA-32industrial, [[x86general-64]]purpose || {{dunno}}NEC V60, NEC V70

|-

| [[SafeRTOS]] || {{proprietary}} || source code & Design Assurance Pack available || embedded, safety critical || active || Same as [[FreeRTOS]]

| [[Micro-Controller Operating Systems|MicroC/OS-II]] || {{proprietary}} || Available under license || embedded || active || ARM7-9-11/Cortex-M1-3-4-A8/9, AVR, HC11/12/S12, ColdFire, Blackfin, MicroBlaze, NIOS, 8051, x86, Win32, H8S, M16C, M32C, MIPS, 68000, PIC24-dsPIC33-PIC32, MSP430, PowerPC, SH, StarCore, [[Renesas]] RX100-200-600-700, RL; STM32, … || {{URL|micrium.com/rtos/ucosii/overview}}

|-

| [[Soft Hard Real-Time Kernel|SHaRK]] || {{free|[[GNU General Public License|GNU GPL]]}}

| [[Micro-Controller Operating Systems|MicroC/OS-III]] || {{proprietary}} || Available under license || embedded || active || ARM7-9-11/Cortex-M1-3-4-A8/9, AVR, HC11/12/S12, ColdFire, Blackfin, MicroBlaze, NIOS, 8051, x86, Win32, H8S, M16C, M32C, MIPS, 68000, PIC24/dsPIC33/PIC32, MSP430, PowerPC, SH, StarCore, [[Renesas]] RX100-200-600-700, RL; STM32, … || {{URL|micrium.com/rtos/ucosiii/overview}}

|open source|| {{dunno}} || inactive || {{dunno}}

|-

| Milos[[Simulink|Simulink Real-Time]] || {{free|[[GNU General Public License|GNU GPL]]proprietary}} || open sourceclosed || real-time testing-embedded || active || Cortex-M3x86 || {{URL|www.milos.it}}

|-

| [[SINTRAN III]] || {{proprietary}} || {{dunno}} || {{dunno}} || {{dunno}} || [[Norsk Data]] computers

| miosix || {{free|[[GNU General Public License|GNU GPL]]}} || open source || embedded || active || stm32, efm32 e LPC2000 || {{URL|www.miosix.org}}

|-

| mipOS[[Symbian OS]] || {{proprietaryfree|[[Eclipse Public License|Eclipse]]}} || open source || embedded || activedefunct || Cortex-M3,ARM ST7, STM8, x86 || {{URL|sites.google.com/site/eantcal/home/mipos}}

|-

| Microsoft Invisible Computing (MMLite) [[T-Kernel]]|| {{proprietaryfree|T-License}} || open source available || embedded RTOS || active || ARM7-9ARM, i386MIPS, h8SH, mips,more Trimedia, eCog1 || {{URL|research.microsoft.com/invisible}}

|-

| mLithOS[[THEOS]] || {{proprietary}} || {{dunno}} || embedded, industrial{{dunno}} || active || LEON2-3-4, x86{{dunno}} || {{URL|www.fentiss.comdunno}}, {{URL|www.xtratum.org}}

|-

| [[ThreadX]] || {{free|[[MIT License|MIT]]}} || open source || embedded, IoT, safety critical || rowspan="2" | active || ARC, ARM/Thumb, AVR32, BlackFin, 680x0-ColdFire, H8-300H, Luminary Micro Stellaris, M-CORE, MicroBlaze, PIC24-dsPIC, PIC32, MIPS, V8xx, Nios II, PowerPC, [[Renesas]] RX100, RX200, RX600, RX700, Synergy, SH, SHARC, StarCore, STM32, StrongARM, TMS320C54x, TMS320C6x, x86/x386, XScale, Xtensa/Diamond, ZSP

| [[MP/M]] || {{proprietary}} || closed (meanwhile: open source) || general purpose, industrial || defunct || 8080, Z80, 8086 || Digital Research

|-

| [[TI-RTOS]] Kernel (SYS/BIOS) || {{free|[[BSD license|BSD]]}} || open source

| [[MQX]] || {{proprietary}} ||complimentary source code available || embedded || active || Freescale Power, ColdFire, Kinetis Cortex ARM, [[List of Freescale products]] || {{URL|www.freescale.com/mqx}}

|embedded|| Mostly Texas Instruments: MSP430-432, C2000-5000-6000, TI's ARM families (Cortex M3-4F-R4-A8-A15), SimpleLink Wireless CC2xxx-CC3xxx

|-

| [[Multi-Environment Real-Time|MERTTizenRT]] || {{dunno}}free|[[Apache License 2.0||Apache {{dunno2.0]]}} || {{dunno}}open source || inactiveembedded || [[PDP-11]]active || {{dunno}}

|-

| [[MultiuserTransaction DOSProcessing Facility]] || {{proprietary}} || closedmixed || general- purpose, industrial || defunctactive || 386[[IBM || Digital Research/Novell, Concurrent Controls, Datapac, IMSZ]] (seeseries REAL/32)

|-

| [[Nano-RKTRON project]] || {{partial|MixedFree}} || open sourcemixed || embedded, [[wireless sensor network|WSN]]mixed || active || AVRany: is a specification, MSP430not ||an implementation {{URL|www.nanork.org}}

|-

| [[UNIX-RTR]] || {{dunno}} || {{dunno}} || {{dunno}} || defunct || [[PDP-11]]

| [[QNX|Neutrino]] || {{proprietary}} || some source code provided || microkernel || active || ARM, MIPS, PPC, SH, x86, XScale || {{URL|www.qnx.com/products/neutrino_rtos}}

|-

| [[UNOS (operating system)|UNOS]] || {{dunno}} || {{dunno}} || {{dunno}} || historic || 680x0

| NI Linux Real-Time || {{proprietary}} || developed from open source || data acquisition and process control || active || National Instruments [[CompactRIO]] controllers || {{URL|http://www.ni.com/white-paper/14627/en/}}

|-

| nOS[[μITRON]] || {{free|[[Mozilla Public T-License|Mozilla]]}} || open source || embedded || active || [[AtmelARM, AVR|AVR]]MIPS, x86, [[TI MSP430|MSP430Renesas]], [[ARM CortexRX100-M|Cortex200-M0600-M3700-M4]],others [[Renesas Electronics#Products|M16C]], [[RX microcontroller family|RX600]], [[PIC microcontroller#PIC24 and dsPIC|PIC24]], [[Windows API|Win32]], [[POSIX]], [[STM8]] || {{URL|github.com/jimtremblay/nOS}}

|-

| [[U-velOSity (microkernel)|μ-velOSity]] || {{proprietary}} || {{dunno}} || microkernel || rowspan="2" | active || {{dunno}}

| [[Nucleus RTOS]] || {{proprietary}} || source code provided || embedded || active || ARM (Cortex-M3-M4-R4-R4F-A8-A9, ARM7-9-11), PowerPC, MIPS32-16e, microMIPS, ColdFire, SuperH || {{URL|www.mentor.com/embedded-software/nucleus}}

|-

| [[U-velOSity (microkernel)|velOSity]] || {{proprietary}} || {{dunno}} || {{dunno}} || Power ISA, ARM/XScale, MIPS, x86/Pentium, ColdFire, Blackfin, OMAP, DaVinci

| NUFR || {{free|Modified [[BSD licenses|BSD]]}} || open source || embedded || active || ARM (Cortex-M0,-M3,-M4) || {{URL|ragingdist.org}}

|-

| [[VAXELN]] || {{proprietary}} || closed source || {{dunno}} || historic || VAX

| [[Ethernut|Nut/OS]] || {{free|[[BSD licenses|BSD]]}} || open source || embedded, industrial || active || AVR, AVR32, [[ARM7#ARM7TDMI .281993.29|ARM7]], [[ARM9]], Cortex-M3 || {{URL|www.ethernut.de/en/firmware/nutos.html}}

|-

| [[Versatile Real-Time Executive|VRTX]] || {{proprietary}} || {{dunno}} || {{dunno}} || superseded by [[Nucleus RTOS]] || ARM, MIPS, PowerPC, [[Reduced instruction set computer|RISC]]

| [[NuttX]] || {{free|[[BSD licenses|BSD]]}} || open source || embedded, small footprint || active || Linux user mode, ARM7-9, Cortex-A5-A8-A9-M0-M3-M4-M7, [[8052]], [[ESP32|Espressif ESP32]], [[LatticeMico32|Lattice LM32]], Renesas MC16C/26/SH-1, [[RISC-V]] , Zilog Z16F, Zilog eZ80 Acclaim!, Zilog Z8Encore!, [[Z80]], MIPS PIC32MX, PIC32MZ|| {{URL|www.nuttx.org}}

|-

| OpenEPOS[[VxWorks]] || {{proprietary}} || open source{{dunno}} || rowspan="3" | embedded || rowspan="4" | active || ARM, x86IA-32, AVRIntel 64, MIPS, PowerPC, ||SH-4, StrongARM, xScale {{URL|epos.lisha.ufsc.br}}

|-

| OS20[[Windows CE]] || {{proprietary}} || closedMicrosoft ||Shared embedded (STB)Source || maintenancex86, onlyMIPS, ||ARM, ST20SuperH || {{dunno}}

|-

| [[Windows 10 IoT]] || {{proprietary}} || {{dunno}} || Intel Atom, Celeron, Pentium; Qualcomm Snapdragon, Broadcom, NXP i.MX

| [[OS2000]] || {{proprietary}} || {{dunno}} || embedded || active || [[MIPS architecture|MIPS]] (Baget-MIPS variant), [[KOMDIV-32]], [[KOMDIV-64]], [[Intel Corporation|Intel]] [[board support package|BSP]]s ([[x86 architecture]]) || {{URL|www.niisi.ru/otd07.htm}}

|-

| [[Xenomai]] || {{free|[[GNU General Public License|GNU GPLv2]]}} || rowspan="2" | open source || general || x86, x86-64, PowerPC, ARM, Analog Devices Blackfin BF52x, BF53x, BF54x and BF56x

| OS21 || {{proprietary}} || source code provided || embedded (STB) || active || ST40/SH4,ST200,ARM || {{dunno}}

|-

| [[OS4000Xinu|XINU]] || {{proprietaryfree}} || closedembedded || process controlactive || maintenancex86, onlyMIPS, ||ARM, GECAVR 4000 series || {{dunno}}

|-

| [[XMK (operating system)|XMK]] || {{free|[[BSD licenses|BSD]]}} || open source || embedded || inactive ||

| OpenRTOS || {{proprietary}} || source code available || embedded || active || Same as [[FreeRTOS]] || {{URL|www.highintegritysystems.com/rtos/openrtos}}

|-

| [[Zephyr (operating system)|Zephyr]]|| {{free|[[Apache License 2.0|Apache 2.0]]}} || open source || embedded || active || [[ARM architecture|ARM]] ([[ARM Cortex-M0|Cortex-M0]], [[ARM Cortex-M3|-M3]], [[ARM Cortex-M4|-M4]], [[ARM Cortex-M23|-M23]], [[ARM Cortex-M33|-M33]], [[ARM Cortex-R|-R4]], [[ARM Cortex-R|-R5]], [[ARM Cortex-A|-A53]]), [[x86]], [[ARC (processor)|ARC]], [[RISC-V]], [[Nios II]], [[Tensilica|Xtensa]], [[SPARC]]

| OSA || {{free|[[BSD licenses|BSD]]}} || open source || embedded || active || PIC10-PIC24, AVR 8-bit, STM8 || {{URL|wiki.pic24.ru/doku.php/en/osa/ref/intro}}

|-

| [[Operating System Embedded|OSE]] || {{proprietary}} || available to customers || general purpose || active || ARM, PowerPC, x86, TI OMAP, … || {{URL|www.enea.com/ose}}

|-

| [[OS-9]] || {{proprietary}} || available to customers || embedded || active || ARM-strongARM, MIPS, PowerPC, SuperH, x86/Pentium, XSCALE, [[Motorola 6809]], 680x0, SPARC || {{URL|www.microware.com}}

|-

| [[OSEK]] || {{partial|Mixed, open source and commercial}} || specification || embedded || active || engine control units || {{URL|www.osek-vdx.org}} (not working for a while), better refer to [http://www.autosar.org www.autosar.org]

|-

| Partikle || {{proprietary}} || {{dunno}} || embedded, industrial || active || LEON2-3-4, x86 || {{URL|www.fentiss.com}}, {{URL|www.xtratum.org}}

|-

| [[IntervalZero|Phar Lap ETS]] || {{dunno}} || {{dunno}} || {{dunno}} || {{dunno}} || {{dunno}} || {{dunno}}

|-

| PaulOS || {{free|[[GNU General Public License|GNU GPL]]}} || open source || embedded || {{dunno}} || {{dunno}} || {{URL|paulos.2038bug.com}}

|-

| PICOS18 || {{free|[[GNU General Public License|GNU GPL]]}} || open source || embedded || {{dunno}} || PIC18 || {{dunno}}

|-

| picoOS || {{free|Modified [[BSD licenses|BSD]]}} || open source || embedded || maintenance || 6502, 80x86, ARM7, AVR, PowerPC,Cortex-M,MSP430,PIC32 || {{URL|picoos.sourceforge.net}},{{URL|github.com/AriZuu/picoos}}

|-

| Piko/RT || {{free|Modified [[BSD licenses|BSD]]}} || open source || embedded || active || ARM Cortex-M3/M4 || {{URL|github.com/pikort/pikoRT}}

|-

| Pharos || {{free|[[Apache License 2.0|Apache 2.0]]}} || open source || embedded, industrial, safety critical || active || ARM926, Cortex-R5, Cortex-M4, Cortex-A53 (all with memory protection)|| {{URL|https://sourceforge.net/projects/rtospharos/}}

|-

| [[Phoenix-RTOS]] || {{proprietary}} || {{dunno}} || embedded || {{dunno}} || ARM7, IA-32, eSI-RISC || {{URL|www.phoenix-rtos.org}}

|-

| [[PikeOS]] || {{proprietary}} || available to customers || safety critical, virtualization || active || PPC, x86, ARM, MIPS, SPARC-LEON, SuperH || {{URL|www.sysgo.com/products/pikeos-rtos-and-virtualization-concept/rtos-technology}}

|-

| Portos || {{proprietary}} || source code provided || embedded, small footprint|| active || (ARM soon) || {{URL|www.portos.org}}

|-

| POK || {{free|[[BSD licenses|BSD]]}} || open source || embedded || active || x86, PowerPC, SPARC || {{URL|pok.safety-critical.net}}

|-

| [[PowerTV]] || {{proprietary}} || {{dunno}} || {{dunno}} || {{dunno}} || {{dunno}} || {{URL|www.powertv.com}}

|-

| [[Prex]] || {{free|[[BSD licenses|BSD]]}} || open source || microkernel || active || ARM, IA-32 || {{URL|prex.sourceforge.net}}

|-

| [[Protothreads]] || {{free|[[BSD licenses|BSD]]}} || open source || general purpose || active || Architecture independent || {{URL|http://dunkels.com/adam/pt/}}

|-

| [[pSOS (real-time operating system)|pSOS]] || {{proprietary}} || {{dunno}} || {{dunno}} || discontinued || 680x0 || {{dunno}}

|-

| [[QNX]] || {{proprietary}} || {{dunno}} || general purpose, medical devices || active || IA-32, MIPS, PowerPC, SH-4, ARM, StrongARM, XScale || {{URL|www.qnx.com}}

|-

| [[QP (framework)|QP]] || {{partial|Dual, open source and commercial}} || dual || MCU, DSC, DSP SoC || active || ARM7/9, ARM Cortex-M3-M0, MSP430, TMS320C28x, AVR, AVRXmega, ColdFire, 68HC08, M16C/R8C, H8, 8051, 80251, PIC18, PIC24/dsPIC33, Nios II, PSoC1 || {{URL|www.state-machine.com/qp}}

|-

| [[:ru:Kaspersky OS|Kaspersky OS]] || {{proprietary}} || {{dunno}} || safety critical, virtualization || active || {{dunno}} || {{dunno}}

|-

| [[Data General RDOS]] || {{proprietary}} || {{dunno}} || general purpose || defunct || [[Data General Nova]], [[Data General Eclipse]] || {{dunno}}

|-

| ReaGOS || {{proprietary}} || closed, available with license || embedded || active || x86, ATmega, ARM, portable || {{URL|www.reagos.com}}

|-

| [[REAL/32]] || {{proprietary}} || closed || general-purpose, industrial || active || 386 || IMS (Multiuser DOS derivative)

|-

| RedHawk Linux (Red Hat compatible) || {{proprietary}} || closed, available with license || embedded || active || x86, others || {{URL|www.ccur.com/linux/products/redhawk}}

|-

| [[Linux kernel#Preemption|Real-time Linux (CONFIG_RT_PREEMPT)]] || {{free|[[GNU General Public License|GNU GPLv2]]}} || open source || general purpose || active || same as [[Linux]] || {{URL|www.osadl.org/Realtime-Linux.projects-realtime-linux.0.html}}, {{URL|rt.wiki.kernel.org}}

|-

| [[REX OS]] || {{proprietary}} || closed, available with license || embedded || inactive || ARM || [[:ja:REX OS]]

|-

| [[RIOT (operating system)|RIOT]] || {{free|[[GNU Lesser General Public License|GNU LGPL]]}} || open source || embedded || active || ARM, MSP430, AVR, x86 || {{URL|www.riot-os.org}}

|-

| [[RMX (operating system)|RMX]] || {{proprietary}} || closed || embedded || defunct || [[Intel 8080|8080]], [[Intel 8086|8086]], [[Intel 80386|80386]] or higher || {{URL|www.tenasys.com/rmx}}

|-

|[[Rodos (operating system)|RODOS]] || {{free|[[BSD licenses|BSD]]}} || source code provided || embedded || active || [[ARM architecture|ARMv7]] (M3, A8, A9), [[AVR32]], [[PowerPC 400|PowerPC 405]], [[SPARC|sparc64]]

Platforms: [https://www.microsemi.com/products/fpga-soc/soc-fpga/smartfusion2 SmartFusion2], [[Raspberry Pi|RaspberryPi]], [[STM32]]

On top of OS: [[Linux]], [[Microsoft Windows|Windows]], [[MacOS]], [[FreeRTOS]], [[RTEMS|RTems]]

|[http://www.montenegros.de/sergio/rodos/rodos-de.html rodos download]

|-

| [[RSX-11]] || {{proprietary}} || {{dunno}} || {{dunno}} || historic || PDP-11 || n/a

|-

| [[RT-11]] || {{proprietary}} || {{dunno}} || general purpose || defunct || PDP-11 || n/a

|-

| [[RTAI]] || {{free|[[GNU General Public License|GNU GPL]]}} || open source || general purpose || active || x86, ARM || {{URL|www.rtai.org}}

|-

| [[RTEMS]] || {{free|[[GNU General Public License|modified GNU GPL]]}} || open source || embedded || active || ARM, Blackfin, ColdFire, TI C3x/C4x, H8/300, x86, 68k, [[Milkymist]] SoC, MIPS, Nios II, PowerPC, SuperH, SPARC, [[ERC32]], LEON, Mongoose-V || {{URL|rtems.com}}

|-

| [[RTLinux]] || {{free|[[GNU General Public License|GNU GPL]]}} || open source || general purpose || inactive || same as [[Linux]] || n/a

|-

| [[RT-Thread]] || {{free|[[Apache License 2.0|Apache 2.0]]}} || open source || embedded || active || ARM, ARM Cortex-M0-M3-R4-M4-M7, IA-32, AVR32, Blackfin, nios, PPC, M16C, MIPS (loongson-1b-1c, PIC32，xburst), MicroBlaze, V850, unicore32, || {{URL|code.google.com/p/rt-thread}}, {{URL|www.rt-thread.org}}

|-

| [[RTXC Quadros]] || {{proprietary}} || source available || embedded || active || ARM - Atmel/Freescale/NXP/[[STM32|ST]]/TI, [[Blackfin]], 680x0-ColdFire, PowerPC, StarCore, TI-Luminary Stellaris, TI OMAP, XScale || {{URL|www.quadros.com/products/operating-systems}}

|-

| [[RTX (operating system)|RTX, RTX64]] || {{proprietary}} || closed || MS Windows extension || active || x86, x86-64 || {{URL|www.intervalzero.com/rtx.htm}}

|-

| RTX Keil Real-Time Operating System || {{proprietary}}, royalty free || source available || embedded || active || ARM || {{URL|www.keil.com/arm/rl-arm/kernel.asp}}

|-

| Ruff || {{proprietary}} || closed || embedded,general purpose, industrial, IoT || active || ARM, MIPS, x86 || {{URL|https://ruff.io/docs/faq.html}}

|-

| [[RX116]] || {{dunno}} || {{dunno}} || embedded, industrial || defunct || [[NEC V20]], [[NEC V30]], [[NEC V40]], [[NEC V50]] || first [[ITRON]] 1 compatible 16-bit RTOS

|-

| [[RX616]] || {{dunno}} || {{dunno}} || safety critical, embedded, industrial || defunct || [[NEC V60]], [[NEC V70]] || 32-bit [[ITRON]] compatible

|-

| [[RX-UX832]] || {{dunno}} || {{dunno}} || embedded, industrial, general-purpose || defunct || NEC V60, NEC V70 || 32-bit Unix-like RTOS

|-

| [[SafeRTOS]] || {{proprietary}} || source code & Design Assurance Pack available || embedded, safety critical || active || Same as [[FreeRTOS]] || Same as [[FreeRTOS]]

|-

| SCIOPTA || {{proprietary}} || closed, source available || embedded, safety related || active || ARM, Cortex-M0-M3-M4, [[ARM Cortex-R4|Cortex-R4]], Cortex-A5, Cortex-A7, Cortex-A9, Cortex-A53, [[XScale]], [[Renesas]] RX100, RX200, RX600, RX700, PowerPC, ColdFire, [[HCS12]], [[M16C]], Windows (simulation), Aurix TC2xx, BlackFin BF52x, BF70x || {{URL|www.sciopta.com}}

|-

| scmRTOS || {{free}} || open source || embedded || active || ARM, Cortex-M3, [[Blackfin]], MSP430, AVR, STM8 || {{URL|scmrtos.sourceforge.net}}

|-

| SDPOS || {{free|[[GNU Lesser General Public License|GNU LGPL]]}} || open source || embedded || active || ARM, Cortex-M3, Blackfin, PIC18, PIC24, i386 win32/linux synthetic targets || {{URL|www.sdpos.org}}

|-

| [[Soft Hard Real-Time Kernel|SHaRK]] || {{free|[[GNU General Public License|GNU GPL]]}} || open source || {{dunno}} || inactive || {{dunno}} || {{URL|shark.sssup.it}}

|-

| silRTOS || {{free}} || open source || embedded || active || ARM, [[ARM Cortex-M3|Cortex-M3 Cortex-A9 ARM-11MP]], [[Blackfin]], MIPS, AVR || {{URL|spanidea.com/products.php}}

|-

| Simba || {{free|[[MIT License|MIT]]}} || open source || embedded || active, beta || Arduino Nano (AVR), Arduino Mega (AVR), Arduino Due (ARM), ESP8266, ESP32, cygwin/linux || {{URL|simba-os.readthedocs.org/en/latest}}

|-

| SimpleAVROS || {{free|[[GNU General Public License|GNU GPLv3]]}} || open source || embedded || active, beta || AVR only || n/a

|-

| [[SINTRAN III]] || {{dunno}} || {{dunno}} || {{dunno}} || {{dunno}} || [[Norsk Data]] computers || n/a

|-

| SOOS Project || {{free}} || open source || embedded || active, beta || [[H8/300]] || {{URL|www.ingelec.uns.edu.ar/rts/soos}}

|-

|StateOS || {{free|[[MIT License|MIT]]}} || open source || embedded, small footprint || active || ARM Cortex-M, STM8 || {{URL|github.com/stateos/StateOS}}

|-

| Stratify OS || {{free|[[GNU General Public License|Modified GNU GPL]] or proprietary}} || open source || embedded || active || ARM Cortex-M3, M4 || {{URL|stratifylabs.co/Stratify-OS/}}

|-

| [[Symbian OS]] || {{free|[[Eclipse Public License|Eclipse]]}} || open source || embedded || defunct || ARM || {{URL|www.symbian.org}}

|-

| [[Talon DSP RTOS]] || {{proprietary}} || {{dunno}} || embedded DSP || active || TMS320 || {{URL|www.blackhawk-dsp.com/Talon.aspx}}

|-

| TargetOS || {{proprietary}} || available to customers || embedded || active || ARM, Cortus, Freescale ColdFire, PowerPC || {{URL|www.blunkmicro.com/os.htm}}

|-

| [[T-Kernel]] || {{free|T-License}} || source available || embedded RTOS || active || ARM, MIPS, SH, more || {{URL|www.t-engine.org}}

|-

| [[THEOS]] || {{dunno}} || {{dunno}} || {{dunno}} || {{dunno}} || {{dunno}} || {{URL|www.theos-software.com}}

|-

| [[ThreadX]] || {{proprietary}} || available to customers || {{dunno}} || active || ARC, ARM/Thumb, AVR32, BlackFin, 680x0-ColdFire, H8-300H, Luminary Micro Stellaris, M-CORE, MicroBlaze, PIC24-dsPIC, PIC32, MIPS, V8xx, Nios II, PowerPC, [[Renesas]] RX100, RX200, RX600, RX700, Synergy, SH, SHARC, StarCore, STM32, StrongARM, TMS320C54x, TMS320C6x, x86/x386, XScale, Xtensa/Diamond, ZSP || {{URL|https://rtos.com/solutions/threadx/}}

|-

| [https://github.com/Samsung/TizenRT TizenRT] || {{free|[[Apache License 2.0|Apache 2.0]]}} || open source || embedded || active || ARM || {{URL|https://github.com/Samsung/TizenRT}}

|-

| [[TI-RTOS]] Kernel (SYS/BIOS) || {{free|[[BSD license|BSD]]}} || open source || embedded || active || Mostly Texas Instruments: MSP430-432, C2000-5000-6000, TI's ARM families (Cortex M3-4F-R4-A8-A15), SimpleLink Wireless CC2xxx-CC3xxx || {{URL|www.ti.com/tool/sysbios}}

|-

|Tock OS|| {{free|[[Apache License 2.0|Apache 2.0]]/[[MIT License|MIT]]}}

|open source

|embedded

|active

|ARM Cortex

|https://www.tockos.org

|-

| Trampoline Operating System (OSEK and AUTOSAR)|| {{free|[[GNU General Public License#Version 2|GNU GPLv2]]}} || open source || embedded || active || AVR, H8-300H, POSIX, [[NEC]] V850e, ARM7, [[Infineon]] C166, [[HCS12]] or PowerPC || {{URL|trampoline.rts-software.org}}

|-

| TNKernel || {{free|[[BSD licenses|BSD]]}} || open source || embedded || active || ARM, PIC24-32-dsPIC, HCS08, STM32 (Cortex-M3) || {{URL|www.tnkernel.com}}

|-

| TNeo || {{free|[[BSD licenses|BSD]]}} || open source || embedded || active || Cortex-M0-M0+-M1-M3-M4-M4F, PIC24-32-dsPIC || {{URL|github.com/dimonomid/tneo}}

|-

| [[Transaction Processing Facility]] || {{proprietary}} || {{dunno}} || general purpose || active || [[IBM]] [[IBM System/360|System/360]] derivatives || {{URL|www.ibm.com/software/htp/tpf}}

|-

| [[TRON project]] || {{Free}} || mixed || mixed || active || any: is a specification, not an implementation || {{URL|www.tron.org/index-e.html}}

|-

| TUD:OS || {{free|[[GNU General Public License|GNU GPL]]}} || open source || {{dunno}} || active || ARM, IA-32, x86-64 || {{URL|demo.tudos.org/eng_about.html}}

|-

| Unison RTOS || {{partial|Mixed, open source and commercial}} || open source || MCU, DSC, DSP SoC, FPGA || active || Pic32, ARM Cortex (TI Stellaris Tiva Sitara, ST STM32, NXP LPC1X00, Freescale iMX6 Kinetis, Renesas RZ, RX600, SH2A, SH2AFPU, R32C, MIPS4K, {SHARC, ColdFire, Xilinx MicroBlaze, proprietary} || {{URL|www.rowebots.com/en/products/unison-rtos-article}}

|-

| [[UNIX-RTR]] || {{dunno}} || {{dunno}} || {{dunno}} || defunct || [[PDP-11]] || {{dunno}}

|-

| uSmartx || {{free|[[BSD licenses|BSD]]}} || open source || embedded || {{dunno}} || ARM7TDMI, AVR, H8 || {{URL|usmartx.sourceforge.net}}

|-

| [[U-velOSity (microkernel)|u-velOSity]] || {{proprietary}} || {{dunno}} || microkernel || active || {{dunno}} || {{URL|www.ghs.com/products/micro_velosity.html}}

|-

| [[U-velOSity (microkernel)|velOSity]] || {{dunno}} || {{dunno}} || {{dunno}} || active || Power Architecture, ARM/XScale, MIPS, x86/Pentium, ColdFire, Blackfin, OMAP, DaVinci || {{URL|www.ghs.com/products/velosity.html}}

|-

| [[Versatile Real-Time Executive|VRTX]] || {{proprietary}} || {{dunno}} || {{dunno}} || superseded by [[Nucleus RTOS]] || ARM, MIPS, PowerPC, [[Reduced instruction set computer|RISC]] || {{URL|www.mentor.com/embedded-software/nucleus}}

|-

| [[VxWorks]] || {{proprietary}} || {{dunno}} || embedded || active || ARM, IA-32, Intel 64, MIPS, PowerPC, SH-4, StrongARM, xScale || {{URL|www.windriver.com/products/vxworks}}

|-

| [[Windows CE]] || {{proprietary}} || Microsoft Shared Source || embedded || active || x86, MIPS, ARM, SuperH || {{URL|www.microsoft.com/windowsembedded}}

|-

| [[Xenomai]] || {{free|[[GNU General Public License|GNU GPLv2]]}} || open source || general || active || x86, x86-64, PowerPC, ARM, Analog Devices Blackfin BF52x, BF53x, BF54x and BF56x || {{URL|www.xenomai.org}}

|-

| [[XMK (operating system)|XMK]] || {{free|[[BSD licenses|BSD]]}} || open source || embedded || inactive-beta || {{dunno}} || {{URL|www.integerfox.com/xmk}}

|-

| [[Simulink|Simulink Real-Time]] || {{proprietary}} || closed || real-time testing-embedded || active || x86 || {{URL|www.mathworks.com/products/simulink-real-time}}

|-

| Y@SOS || {{free|[[GNU Lesser General Public License|GNU LGPL]]}} || open source || embedded || active || Cortex-M3, STM32 || {{URL|www.yasos.org}}

|-

| [[MontaVista Linux]] || {{free|[[GNU General Public License|GNU GPL]]}} || open source || embedded || active || {{dunno}} || {{URL|www.mvista.com}}

|-

| [[UNOS (operating system)|UNOS]] || {{dunno}} || {{dunno}} || {{dunno}} || historic || 680x0 || {{dunno}}

|-

| uOS || {{free|[[GNU General Public License|GNU GPL]]}} || open source || embedded || active || AVR, ARM, MIPS32, MSP430, Intel i386, Linux386 || {{URL|code.google.com/p/uos-embedded/wiki/about}}

|-

| [[Zephyr (operating system)|Zephyr]] || {{free|[[Apache License 2.0|Apache 2.0]]}} || open source || embedded || active || [[ARM architecture|ARM]] ([[ARM Cortex-M0|Cortex-M0]], [[ARM Cortex-M3|Cortex-M3]], [[ARM Cortex-M4|Cortex-M4]], [[ARM Cortex-M23|Cortex-M23]], [[ARM Cortex-M33|Cortex-M33]]), [[x86]], [[ARC (processor)|ARC]], [[RISC-V]], [[Nios II]], [[Tensilica|Xtensa]] || {{URL|http://www.zephyrproject.org/}}

|}

==References==

== External links ==

{{Reflist}}

*{{Dmoz|Computers/Software/Operating_Systems/Realtime}}

==External links==

* [https://github.com/user-attachments/files/17348393/Beningo-RtosPerformance-2024-Report.pdf 2024 RTOS Performance Report] (FreeRTOS / ThreadX / PX5 / Zephyr) - Beningo Embedded Group

* [https://web.archive.org/web/20170904172524/http://www.embedded.com/design/operating-systems/4425751/2/Comparing-microcontroller-real-time-operating-systems 2013 RTOS Comparison] (Nucleus / ThreadX / ucOS / Unison) - Embedded Magazine

{{Real-time operating systems}}