Comparison of real-time operating systems


This is a list of real-time operating systems. 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.
NameLicenseSource modelTarget usesStatusPlatforms
Apache Mynewtopen sourceembeddedactiveARM Cortex-M, MIPS32, Microchip PIC32, RISC-V
BeRTOSopen sourceembeddedarchivedARM, Cortex-M3, ARM ARM7TDMI, Atmel AVR, PowerPC, x86, x86-64
ChibiOS/RTopen sourceembedded, small footprintactivex86, ARM7, ARM9, Cortex-M0-M3-M4, PowerPC e200z, STM8, STM32, AVR, MSP430, ColdFire, H8S
ChorusOSdefunctSPARC, x86, PowerPC
Contikiopen sourceembedded, WSNactiveMSP430, AVR, ARM
Data General RDOSgeneral purposedefunctData General Nova, Data General Eclipse
Deosclosedsafety criticalactivex86, PowerPC, ARM, MIPS
DioneOSavailable for licenseeembeddedactiveMSP430, MSP430x
DNIXclosedgeneral purposedefunct68000
GEC DOSclosedprocess controldefunctGEC 4000 series
DSOScloseddefunctTI-980A minicomputer
DSP/BIOSclosed, available with licensegeneral purposemaintenance onlyMostly Texas Instruments C2800, C5500, C6000 and OMAP DSP cores. Replaced by TI-RTOS, but available for download.
eCosopen sourceembeddedinactiveARM-XScale-Cortex-M, CalmRISC, 680x0-ColdFire, fr30, FR-V, H8, IA-32, MIPS, MN10300, OpenRISC, PowerPC, SPARC, SuperH, V8xx
eCosProopen source with non-free portionsembeddedactiveARM7-9, 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
embOSclosed, available to customers, free object code for non-commercial useembedded, industrial, IoT, safety criticalactiveARM7/9/11, 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
ERIKA Enterpriseopen sourceembeddedactiveARM7, ARM Cortex-M, ARM Cortex-A, Hitachi H8, Altera Nios2, Microchip dsPIC, Microchip PIC32, ST Microelectronics ST10, Infineon C167, Infineon Tricore, Freescale PPC e200, Freescale S12XS, EnSilica eSi-RISC, AVR, Lattice Mico32, MSP430, Renesas RX200, x86-64
EROSopen sourceexperimental
research use		dormantIA-32
FlexOSclosedgeneral purpose, industrial, POSdefunct186, 286, 386, V60, V70, 68000
FreeRTOSopen sourceembeddedactiveARM, 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
Fuchsiaopen sourceembeddedactiveAArch64, x86-64
Keil RTXopen sourceembeddedactiveArm Cortex-M
FunkOSopen sourceembeddedactiveAVR, MSP430, Cortex-M3
HeartOSclosedsafety criticalactivex86, PowerPC, ARM
Huawei LiteOSopen sourceembeddeddefunctARM, x86, RISC-V
HarmonyOSclosedembeddedactiveAArch64, x86-64, RISC-V, LingxiISA
IBM 4680 OSclosedgeneral purpose, industrial, POSdefunct286
IBM 4690 OSclosedgeneral purpose, industrial, POSactive286, 386
INTEGRITYclosedembeddedactiveARM, XScale, Blackfin, ColdFire, MIPS, PowerPC, x86
INtimeclosedembeddedactivex86
ITRONvariesembeddedactiveARM, MIPS, x86, Renesas RX100-200-600-700-others
Kaspersky OSopen sourcesafety critical, virtualizationactivex86, x86_64, ARMV5, ARMV7, ARMV8, MIPS32
KolibriOSopen sourceembeddableactivex86
LynxOSsource availableembeddedactiveMotorola 68010, x86/IA-32, ARM, Freescale PowerPC, PowerPC 970, LEON
Mbed OSopen sourceembeddedabandonedArm Cortex-M
MenuetOSopen sourceactiveIA-32
MERTclosedOS for long-distance telephone switching systemsinactivePDP-11
MicroC/OS-IIIopen sourceembeddedactiveARM7-9-11/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,...
MontaVista Linuxopen sourceembedded
MP/Mclosed general purpose, industrialdefunct8080, Z80, 8086
MQXcomplimentary source availableembeddedactiveFreescale Power, ColdFire, Kinetis Cortex ARM, List of Freescale products
Multiuser DOSclosedgeneral-purpose, industrialdefunct386
Nano-RKopen sourceembedded, WSNdefunctAVR, MSP430
Neutrinosome source providedmicrokernel, embedded, industrialactiveARM, ARM64, MIPS, PPC, SH, x86, x86-64, XScale
Nucleus RTOSsource providedembeddedactiveARM, PowerPC, MIPS32-16e, microMIPS, ColdFire, SuperH
NUTopen sourceembedded, industrialactiveARM-M0, ARM-M0+, ARM Cortex-M3, ARM9, ARM Cortex-M7, Cortex-M3
Nut/OSopen sourceembedded, industrialactiveAVR, AVR32, ARM7, ARM9, Cortex-M3
NuttXopen sourceembedded, small footprintactiveLinux user mode, ARM7-9, Cortex-A5-A8-A9-M0-M3-M4-M7, 8052, Espressif ESP32, Lattice LM32, Renesas MC16C/26/SH-1, RISC-V, Zilog Z16F, Zilog eZ80 Acclaim!, Zilog Z8Encore!, Z80, MIPS PIC32MX, PIC32MZ
OpenComRTOSsource providedembeddedactiveFreescale PowerPC, Texas Instruments C66xxx DSP, ARM, XMOS, MicroBlaze, LEON, NXP CoolFlux DSP, Melexis MLX16, Win32, Linux
OS2000embeddedactiveMIPS, KOMDIV-32, KOMDIV-64, Intel BSPs
OS4000closedprocess controlmaintenance onlyGEC 4000 series
OSEavailable to customersgeneral purposeactiveARM, PowerPC, x86, TI OMAP,...
OS-9available to customersembeddedactiveARM-strongARM, MIPS, PowerPC, SuperH, x86/Pentium, XSCALE, Motorola 6809, 680x0, SPARC
OSEKspecificationembeddedactiveengine control units
Phoenix-RTOSopen sourceembeddedactiveARMv7 Cortex-M, ARMv7 Cortex-A, IA-32, RISC-V
PikeOSavailable to customerscertifiable safety & security, embedded virtualisationactivePPC, x86, ARM, MIPS, SPARC-LEON, RISC-V
Protothreadsopen sourcegeneral purposeactiveArchitecture independent
pSOSdiscontinued680x0
PX5 RTOSroyalty-free licensingembeddedactiveEmbedded MCU and MPU architectures. ARM's Cortex-M, Cortex-R, Cortex-A, RISC-V. AMP and SMP configurations.
QNXmicrokernel, embedded, industrialactiveactive
QPdualMCU, DSC, DSP SoCactiveARM7/9, ARM Cortex-M3-M0, MSP430, TMS320C28x, AVR, AVRXmega, ColdFire, 68HC08, M16C/R8C, H8, 8051, 80251, PIC18, PIC24/dsPIC33, Nios II, PSoC1
REAL/32closedgeneral-purpose, industrialactive386
Real-time Linux open sourcegeneral purposeactivex86, x86_64, RISC-V, ARM64 and LoongArch
REX OSclosed, available with licenseembeddedinactiveARM
RIOTopen sourceembeddedactiveARM7, ARM Cortex M, MSP430, AVR, RISC-V, Xtensa
RMXclosedembeddeddefunctIntel 8080, 8086, 80386, higher
RODOSsource providedembeddedactiveARMv7, AVR32, PowerPC 405, SPARC64
Platforms: SmartFusion2, RaspberryPi, STM32
On an OS: Linux, Windows, macOS, FreeRTOS, RTEMS
RSX-11historicPDP-11
RT-11general purposedefunctPDP-11
RTAIopen sourcegeneral purposeactivex86, x86-64, PowerPC, ARM, m68k
RTEMSopen sourceembeddedactiveAArch64, 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
RTLinuxopen sourcegeneral purposeinactivesame as Linux
RT-Threadopen sourceembeddedactiveARM, ARM Cortex-M0-M3-R4-M4-M7, IA-32, AVR32, Blackfin, nios, PPC, M16C, MIPS, MicroBlaze, V850, unicore32,
RTXC Quadrossource availableembeddedactiveARM - Atmel/Freescale/NXP/ST/TI, Blackfin, 680x0-ColdFire, PowerPC, StarCore, TI-Luminary Stellaris, TI OMAP, XScale
RTX, RTX64closedMS Windows extensionactivex86, x86-64
RX116embedded, industrialdefunctNEC V20, NEC V30, NEC V40, NEC V50
RX616safety critical, embedded, industrialdefunctNEC V60, NEC V70
RX-UX832embedded, industrial, general-purposedefunctNEC V60, NEC V70
SafeRTOSsource code & Design Assurance Pack availableembedded, safety criticalactiveSame as FreeRTOS
SHaRKopen sourceinactive
Simulink Real-Timeclosedreal-time testing-embeddedactivex86
SINTRAN IIINorsk Data computers
Symbian OSopen sourceembeddeddefunctARM
T-Kernelsource availableembedded RTOSactiveARM, MIPS, SH, more
THEOS
ThreadXopen sourceembedded, IoT, safety criticalactiveARC, 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
TI-RTOS Kernel open sourceembeddedactiveMostly Texas Instruments: MSP430-432, C2000-5000-6000, TI's ARM families, SimpleLink Wireless CC2xxx-CC3xxx
TizenRTopen sourceembeddedactive
Transaction Processing Facilitymixedgeneral purposeactiveIBM Z series
TRON projectmixedmixedactiveany: is a specification, not an implementation
UNIX-RTRdefunctPDP-11
UNOShistoric680x0
μITRONopen sourceembeddedactiveARM, MIPS, x86, Renesas RX100-200-600-700-others
μ-velOSitymicrokernelactive
velOSityactivePower ISA, ARM/XScale, MIPS, x86/Pentium, ColdFire, Blackfin, OMAP, DaVinci
VAXELNclosed sourcehistoricVAX
VRTXsuperseded by Nucleus RTOSARM, MIPS, PowerPC, RISC
VxWorksembeddedactiveARM, IA-32, Intel 64, MIPS, PowerPC, SH-4, StrongARM, xScale
Windows CEMicrosoft Shared Sourceembeddedactivex86, MIPS, ARM, SuperH
Windows 10 IoTembeddedactiveIntel Atom, Celeron, Pentium; Qualcomm Snapdragon, Broadcom, NXP i.MX
Xenomaiopen sourcegeneralactivex86, x86-64, PowerPC, ARM, Analog Devices Blackfin BF52x, BF53x, BF54x and BF56x
XINUopen sourceembeddedactivex86, MIPS, ARM, AVR
XMKopen sourceembeddedinactive
Zephyropen sourceembeddedactiveARM, x86, ARC, RISC-V, Nios II, Xtensa, SPARC