Open Source Real-Time Operating Systems

Contribute

Name	License	Platforms	Components	Version	Links	Last updated
RIOT	LGPL-2.1	arm-cortex-m risc-v xtensa avr msp430 posix	scheduler task-management inter-task-communication memory-management timer-management network-stack ble lorawan 6lowpan coap mqtt-client usb-device filesystem ota-update shell-cli logging simulation runtime-analysis crypto	2025.01	Code Website 5499	2025-04-13
NuttX	Apache-2.0	aarch32 aarch64 arm-cortex-a arm-cortex-r arm-cortex-m x86 x86_64 risc-v mips avr hcs12 sparc superh z80 xtensa qemu posix	scheduler task-management inter-task-communication memory-management timer-management network-stack ble wifi lorawan 6lowpan http-client http-server mqtt-client coap ftp-client ftp-server snmp-agent dhcp-client dhcp-server dns-client tls-ssl filesystem usb-host usb-device can modbus at-command shell-cli logging ota-update dynamic-loading smp-support gui runtime-analysis simulation	nuttx-12.9.0-RC1	Code Website 3222	2025-04-13
RT-Thread	Apache-2.0 GPL-2.0	arm-cortex-m arm-cortex-r arm-cortex-a risc-v mips xtensa x86 qemu posix	scheduler task-management inter-task-communication memory-management timer-management filesystem shell-cli network-stack http-client mqtt-client tls-ssl usb-host usb-device can modbus gui logging ota-update runtime-analysis simulation at-command wifi ble lorawan 6lowpan coap ftp-client dns-client dhcp-client	v5.2.0	Code Website 10993	2025-04-13
TizenRT	Apache-2.0	arm-cortex-m arm-cortex-r xtensa qemu posix	scheduler task-management inter-task-communication memory-management timer-management network-stack wifi http-client http-server mqtt-client coap grpc http2 ftp-client dhcp-client dhcp-server dns-client tls-ssl filesystem database shell-cli logging runtime-analysis simulation	3.0_GBM	Code Website 609	2025-04-12
Zephyr	Apache-2.0	aarch32 aarch64 arm-cortex-a arm-cortex-r arm-cortex-m x86 risc-v mips nios-ii xtensa sparc posix qemu	scheduler task-management inter-task-communication memory-management timer-management network-stack ble wifi lorawan 6lowpan http-client http-server mqtt-client coap dhcp-client dhcp-server dns-client tls-ssl filesystem usb-host usb-device can modbus shell-cli logging ota-update smp-support gui runtime-analysis simulation	v4.1.0	Code Website 11878	2025-04-12
Apache Mynewt	Apache-2.0	arm-cortex-m risc-v mips posix	scheduler task-management inter-task-communication memory-management timer-management network-stack ble 6lowpan coap dhcp-client dns-client tls-ssl filesystem shell-cli logging ota-update runtime-analysis	pre_sterly_refactor	Code Website 863	2025-04-11
Hubris	MPL-2.0	arm-cortex-m	scheduler task-management inter-task-communication memory-management timer-management logging runtime-analysis	sidecar-v1.0.37	Code Website 3141	2025-04-10
Tock	Apache-2.0 MIT	arm-cortex-m risc-v	scheduler task-management inter-task-communication memory-management timer-management logging dynamic-loading filesystem	release-2.2	Code Website 5726	2025-04-10
Phoenix-RTOS	BSD-3-Clause	arm-cortex-m arm-cortex-a x86 risc-v sparc posix	scheduler task-management inter-task-communication memory-management filesystem network-stack tls-ssl http-client http-server mqtt-client wifi usb-host usb-device shell-cli logging gui	v3.3.2	Code Website 134	2025-04-09
embox	BSD-3-Clause	arm-cortex-m arm-cortex-a aarch64 x86 risc-v mips powerpc microblaze sparc qemu posix	scheduler task-management inter-task-communication memory-management timer-management network-stack http-client http-server dhcp-client dns-client tls-ssl mqtt-client filesystem usb-host usb-device shell-cli logging gui smp-support simulation	v0.6.5	Code Website 1361	2025-04-09
Mongoose OS	Apache-2.0 Commercial	arm-cortex-m xtensa	scheduler task-management timer-management network-stack wifi http-client http-server mqtt-client tls-ssl filesystem ota-update shell-cli logging	2.20.0	Code Website 2547	2025-04-08
FreeRTOS	MIT	arm-cortex-m arm-cortex-a arm-cortex-r risc-v xtensa x86 mips powerpc avr pic 8051 msp430 posix qemu	scheduler task-management inter-task-communication memory-management timer-management network-stack mqtt-client http-client tls-ssl ota-update logging runtime-analysis smp-support	202411.00	Code Website 5882	2025-04-08
qpc	GNU GPLv3 Commercial License (Quantum Leaps)	ARM Cortex-M	Active Objects	v8.0.3	Code Website 1068	2025-04-07
ChibiOS/RT	Modified GPL or Apache	MSP430 AVR ColdFire PowerPC STM32	FileSystem Network USBHost USBDevice	ver21.11.3	Code Website 748	2025-04-07
seL4	GPL v2	ARM x86 RISC-V		13.0.0	Code Website 4883	2025-04-04
RTIC	Apache License, Version 2.0 MIT license	ARM		v2.1.1	Code Website 1946	2025-04-03
Contiki-NG	3-clause BSD license	ARM MSP430	FileSystem Network 6LoWPAN Database Simulation Shell	release/v5.0	Code Website 1386	2025-03-27
Eclipse ThreadX	MIT	arm-cortex-m arm-cortex-a arm-cortex-r risc-v xtensa arc mips nios-ii microblaze powerpc posix	scheduler task-management inter-task-communication memory-management timer-management network-stack filesystem usb-host usb-device gui dynamic-loading smp-support runtime-analysis tls-ssl http-client http-server mqtt-client dhcp-client dhcp-server dns-client ftp-client ftp-server snmp-agent	v6.4.2_rel	Code Website 3095	2025-02-27
TNeo	Other	ARM		v1.09	Code Website 236	2024-12-28
distortos	Mozilla Public License Version 2.0	ARM		v0.7.0	Code Website 452	2024-11-27
RA3-RTOS	MIT License	ARM	Task Management Scheduling Memory Management Inter-task Communication	v-1.0.0	Code Website 2	2024-11-04
QuarkTS	LGPL	ARM AVR PIC ColdFire MSP430 8051 MIPS HCS12 x86		7.3.3	Code Website 319	2024-10-28
mbed OS	Apache License	ARM	BLE LoRaWAN FileSystem Network 6LoWPAN AT Commands TLS/SSL Runtime Analysis USBHost USBDevice	mbed-os-6.17.0	Code Website 4736	2024-10-08
HuskEOS	MIT license	ARM		dev	Code Website 2	2024-09-11
CMSIS Version 5	Apache-2.0 license	ARM		5.9.0	Code Website 1423	2024-09-03
RTEMS	BSD	AArch64 BlackFin i386 lm32 m68k, ColdFire Microblaze MIPS Moxie Nios 2 OR1K PowerPC RISC-V SuperH (sh) SPARC (LEON) SPARC64 V850 x86	FileSystem TLS/SSL Dynamic Loading SMP Command Line Interface	6.1	Code Website 585	2024-06-11
StratifyOS	GPL	ARM		compilerv11	Code Website 138	2024-06-07
IntrOS	MIT	ARM, STM8, AVR8		v4.9	Code Website 41	2024-04-23
StateOS	MIT	ARM Cortex-M, STM8		v6.9	Code Website 194	2024-04-23
Trampoline	GPL v2	ARM AVR PowerPC		dev-master	Code Website 669	2024-03-20
TencentOS-tiny	BSD 3-Clause License	ARM	BLE LoRaWAN FileSystem TLS/SSL Network GUI	v2.5.0	Code Website 5982	2024-02-02
LibreRTOS	Apache License	AVR		dev-master	Code Website 39	2023-12-01
AliOS Things	Apache License	ARM		v1.3.4	Code Website 4611	2023-07-04
uC/OS-II	Apache License 2.0	ARM ColdFire AVR AVR32 80X86 PowerPC RISC-V MSP430 PIC32	FileSystem Network TLS/SSL USBHost USBDevice Modbus GUI CAN	v2.93.01	Code Website 616	2023-01-05
uC/OS-III	Apache License 2.0	ARM ColdFire AVR AVR32 80X86 PowerPC RISC-V MSP430 PIC32	FileSystem Network TLS/SSL USBHost USBDevice Modbus GUI CAN	v3.08.02	Code Website 951	2022-12-02
Drone	Apache License 2.0 MIT license	ARM		v0.14.3	Code Website 479	2022-11-20
Apex	Other	ARM RISC-V QEMU	FileSystem Shell	dev	Code Website 31	2022-05-30
TinyOS	BSD	MSP430 AVR		release_tinyos_2_1_2	Code Website 1439	2021-04-22
scmRTOS	MIT	MSP430 AVR		v5.2.0	Code Website 228	2021-02-04
Nut/OS	GPL	AVR ColdFire			Code Website	2021-01-15
LiteOS	BSD	ARM		LiteOSV200R001C50B039	Code Website 4861	2020-12-30
DuinOS	Other	AVR		FreeRTOS_V7.4.0	Code Website 74	2020-07-10
F9 Microkernel	BSD	ARM			Code Website 688	2020-01-01
MOE	MIT	ARM		V0.1.6	Code Website 68	2019-12-08
Erika Enterprise	Modified GPL	MSP430 ARM AVR		GH65	Code Website 190	2019-09-12
Frosted	GPL v2	ARM		old_hal_lpc	Code Website 218	2019-06-14
eChronos	Other	ARM PowerPC POSIX		v3.0.5	Code Website 173	2019-06-12
HyperC	Other	ARM ARM Cortex		eva3	Code Website 3	2019-02-13
Contiki OS	BSD	MSP430 ARM AVR 8051	FileSystem Network 6LoWPAN Command Line Interface	3.0	Code Website 3752	2018-11-03
BeRTOS	Modified GPL	AVR x86 PowerPC x86_64			Code Website 122	2018-08-09
Xenomai	GPL	ARM x86 PowerPC	FileSystem Network TLS/SSL	v3.0.7	Code Website	2018-07-25
cocoOS	BSD	MSP430 ARM AVR		5.0.1	Website	2018-06-15
BRTOS	MIT	MSP430 AVR ColdFire PIC			Code Website 78	2018-03-01
RTAI	GPL	ARM x86 PowerPC x86_64 m68k		RTAI 5.1	Code Website	2018-02-05
Atomthreads	BSD	AVR		release1.3	Code Website 422	2017-08-27
uKOS	GPL v3	ARM		4.0.0	Website	2017-04-26
ATK2	Other	Nios II		1.4.2	Code Website	2017-03-24
MaRTE	GPL v2	ARM x86	Network Logging	2.0	Website	2017-02-22
BitThunder	GPL v2	ARM		stable-0.9.2	Code Website 170	2017-01-25
TI-RTOS Kernel	Other			v3.00.00	Website	2016-07-09
Fusion Embedded RTOS	Other	ARM PowerPC			Website	2015-03-08
MARK3	BSD	AVR			Code Website	2015-03-08
Freescale MQX	Other	ARM ColdFire		4.2.0	Website	2015-03-07
eCos	GPL	ARM MIPS PowerPC			Website	2013-08-25
TNKernel	GPL	MSP430 ColdFire			Website	2013-06-06
FunkOS	Other	MSP430 AVR			Website	2013-04-23
Femto OS	GPL	AVR			Code Website	2010-04-24
Prex	BSD	ARM x86		0.9.0	Code Website	2009-10-01
uSmartX	BSD	ARM AVR		1.34	Code Website	2006-01-14
Protothreads	BSD	AVR 8051			Website	2005-04-08