NuttX Apache License 2.0 ARM

AVR

8051

PIC

x86

MIPS

Xtensa

RISC-V

Freescale HCS12

Zilog FileSystem

Network

6LoWPAN

Command Line Interface

USBHost

USBDevice

GUI NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 32-bit microcontroller environments, the primary governing standards in NuttX are Posix and ANSI standards. nuttx-9.1.0 Code

Code Website 2020-08-23

Apache Mynewt Apache License ARM

MIPS BLE

LoRaWAN

FileSystem

Network

6LoWPAN

TLS/SSL

Runtime Analysis Apache Mynewt OS is a real-time, modular operating system for connected IoT devices that need to operate for long periods of time under power, memory, and storage constraints. It provides a complete environment for prototyping, developing, and managing em pre_sterly_refactor Code

Code Website 2020-08-23

ChibiOS/RT Modified GPL or Apache MSP430

AVR

ColdFire

PowerPC

STM32 FileSystem

Network

USBHost

USBDevice ChibiOS is a complete development environment for embedded applications including RTOS, an HAL, peripheral drivers, support files and a development environment. 20.3.2 Code

Code Website 2020-08-22

Phoenix BSD ARM

x86

RISC-V FileSystem

Network

USBDevice Phoenix-RTOS is an open-source, microkernel-based, realtime operating system for resource constrained devices. dev Code

Code Website 2020-08-20

mbed OS Apache License ARM BLE

LoRaWAN

FileSystem

Network

6LoWPAN

AT Commands

TLS/SSL

Runtime Analysis

USBHost

USBDevice mbed OS is an open-source embedded operating system designed specifically for the “things” in the Internet of Things (IoT). It includes all the features you need to develop a connected product based on an ARM Cortex-M microcontroller. mbed-os-6.2.1 Code

Code Website 2020-08-19

QuarkTS LGPL ARM

AVR

PIC

ColdFire

MSP430

8051

MIPS

HCS12

x86 QuarkTS is a simple non-Preemtive Real-Time OS with a quasi-static scheduler for embedded multi-tasking applications. 6.3.3 Code

Code Website 2020-08-17

Azure RTOS Other ARM Cortex M FileSystem

Network

Runtime Analysis

GUI

USBHost

USBDevice This advanced real-time operating system (RTOS) is designed specifically for deeply embedded applications. Among the multiple benefits it provides are advanced scheduling facilities, message passing, interrupt management, and messaging services. Azure RTOS ThreadX has many advanced features, including picokernel architecture, preemption threshold, event chaining, and a rich set of system services. v6.0.2_rel Code

Code Website 2020-08-14

TencentOS-tiny BSD 3-Clause License ARM BLE

LoRaWAN

FileSystem

TLS/SSL

Network

GUI TencentOS tiny is a real-time operating system developed by Tencent for the Internet of Things. It features low power consumption, low resource consumption, modularity, security and reliability, and can effectively improve the development efficiency of IoT terminal products. dev-master Code

Code Website 2020-08-11

RIOT LGPLv2.1 MSP430

ARM

AVR

MIPS

RISC-V BLE

LoRaWAN

FileSystem

Network

6LoWPAN

GUI

TLS/SSL

USBDevice

OTA RIOT is a real-time multi-threading operating system that supports a range of devices that are typically found in the Internet of Things (IoT): 8-bit, 16-bit and 32-bit microcontrollers. 2020.07 Code

Code Website 2020-07-24

Nut/OS GPL AVR

ColdFire Nut/OS is an intentionally simple RTOS for the ATmega128, which provides a minimum of services to run Nut/Net, the TCP/IP stack. Code

Code Website 2020-07-18

DuinOS Other AVR DuinOS is a small multithreading real time operating system (RTOS), based on the FreeRTOS kernel, for Arduino compatible boards. FreeRTOS_V7.4.0 Code

Code Website 2020-07-10

StateOS MIT ARM Cortex-M, STM8 Free, extremely simple and amazingly tiny real-time operating system (RTOS) designed for deeply embedded applications. Target: ARM Cortex-M, STM8. It was inspired by the concept of a state machine. v6.7 Code

Code Website 2020-07-08

IntrOS MIT ARM, STM8, AVR8 Free, simple and tiny cooperative operating system (OS) designed for deeply embedded applications. v4.7 Code

Code Website 2020-07-08

embox Other MSP430

ARM

MIPS

PowerPC Embox is a configurable operating system kernel designed for resource constrained and embedded systems. v0.4.2 Code

Code Website 2020-07-01

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 µC/OS-III is a highly portable, ROMable, scalable, preemptive, real-time, deterministic, multitasking kernel for microprocessors, microcontrollers and DSPs. v3.08.00 Code

Code Website 2020-07-01

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 μC/OS-II is a portable, ROMable, scalable, preemptive, real-time deterministic multitasking kernel for microprocessors, microcontrollers and DSPs. v2.93.00 Code

Code Website 2020-07-01

Zephyr Apache License ARM

x86

Xtensa

RISC-V

ARC

Nios II BLE

FileSystem

Command Line Interface

Logging The Zephyr™ Project is a scalable, real-time operating system (RTOS) supporting multiple hardware architectures, optimized for resource constrained devices, and built with security in mind. This Linux Foundation hosted project embraces open source development values and governance on its mission to unite leaders from across the industry to produce a best-in-breed solution. zephyr-v2.3.0 Code

Code Website 2020-06-05

Trampoline GPL v2 ARM

AVR

PowerPC Trampoline is a static RTOS for small embedded systems. Its API is aligned with OSEK/VDX OS and AUTOSAR OS 4.2 standards. dev-master Code

Code Website 2020-06-02

TinyOS BSD MSP430

AVR TinyOS is an open source, BSD-licensed operating system designed for low-power wireless devices, such as those used in sensor networks, ubiquitous computing, personal area networks, smart buildings, and smart meters. release_tinyos_2_1_2 Code

Code Website 2020-05-30

Contiki-NG 3-clause BSD license ARM

MSP430 FileSystem

Network

6LoWPAN

Database

Simulation

Shell Contiki-NG is an operating system for resource-constrained devices in the Internet of Things. Contiki-NG contains an RFC-compliant, low-power IPv6 communication stack, enabling Internet connectivity. release/v4.5 Code

Code Website 2020-05-14

RT-Thread Modified GPL v2 ARM

x86

MIPS

PowerPC

RISC-V

Andes FileSystem

Network

AT Commands

Command Line Interface

Runtime Analysis

USBHost

USBDevice RT-Thread is an open source real-time operating system for embedded devices from China. RT-Thread RTOS is a scalable real-time operating system: a tiny kernel for ARM Cortex-M0, Cortex-M3/4, or a full feature system in ARM Cortex-A8, ARM Cortex-A9 DualCor v3.1.4 Code

Code Website 2020-05-13

Drone Apache License 2.0

MIT license ARM Drone is an Embedded Operating System for writing real-time applications in Rust. v0.12.1 Code

Code Website 2020-05-13

Tock Apache License 2.0 ARM Tock is an embedded operating system designed for running multiple concurrent, mutually distrustful applications on Cortex-M based embedded platforms. The kernel and device drivers are written in Rust. release-1.5 Code

Code Website 2020-04-30

AliOS Things Apache License ARM AliOS Things is designed for low power, resource constrained MCU, connectivity SoC, greatly suitable for IoT devices. AliOS Things is not just a RTOS, it contains full stack of software components and tools for building IoT devices. v3.1.0 Code

Code Website 2020-04-10

FreeRTOS MIT MSP430

ARM

AVR

ColdFire

PIC

x86 FileSystem

Network

TLS/SSL

Command Line Interface

Runtime Analysis FreeRTOS is a market leading RTOS from Amazon Web Services that supports more than 35 architectures. It is distributed under the MIT license. V10.3.1 Code

Code Website 2020-02-19

Mongoose OS GPL v2 ARM

Xtensa FileSystem

Network

TLS/SSL Mongoose OS - an open source Operating System for Internet of Things. Supported microcontrollers: ESP32, ESP8266, CC3220, CC3200, STM32F4. Amazon AWS IoT & Google IoT Core integrated. Code in C or JavaScript. 2.17.0 Code

Code Website 2020-01-31

F9 Microkernel BSD ARM F9 microkernel is a microkernel-based (L4-style) kernel to support running real-time and time-sharing applications (for example, wireless communications) for ARM Cortex-M series microprocessors with efficiency (performance + power consumption) and security (memory protection + isolated execution) in mind. Code

Code Website 2020-01-01

TizenRT Apache License 2.0 ARM TizenRT is a lightweight RTOS-based platform to support low-end IoT devices 3.0_GBM Code

Code Website 2019-12-11

seL4 GPL v2 ARM

x86

RISC-V The world’s first operating-system kernel with an end-to-end proof of implementation correctness and security enforcement is available as open source. 11.0.0 Code

Code Website 2019-11-20

Erika Enterprise Modified GPL MSP430

ARM

AVR Erika Enterprise is the first open-source Free RTOS that has been certified OSEK/VDX compliant!. GH65 Code

Code Website 2019-09-12

LiteOS BSD ARM Huawei LiteOS is a lightweight open-source IoT OS and a smart hardware development platform. It simplifies IoT device development and device connectivity, makes services smarter, delivers superb user experience, and provides better data protection. Huawei LiteOS is designed for smart homes, wearables, IoV, and intelligent manufacturing applications. LiteOSV200R001C50B039 Code

Code Website 2019-08-01

Frosted GPL v2 ARM Frosted is an acronym that means “Free Operating Systems for Tiny Embedded Devices”. The goal of this project is to provide a Free (as in Freedom) kernel for embedded systems, which exposes a POSIX-compliant system call API. old_hal_lpc Code

Code Website 2019-06-14

distortos Mozilla Public License Version 2.0 ARM distortos is an object-oriented C++ RTOS for microcontrollers. v0.7.0 Code

Code Website 2019-05-05

HyperC Other ARM

ARM Cortex The hyperC OS is a real time-operating system (RTOS) designed for various IoT applications. All the designs are aimed at the optimization of ARM Cortex CPUs. eva3 Code

Code Website 2019-02-13

eChronos Other ARM

PowerPC

POSIX The eChronos RTOS is a real-time operating system (RTOS) originally developed by NICTA and Breakaway Consulting Pty. Ltd. It is intended for tightly resource-constrained devices without memory protection. v3.0.5 Code

Code Website 2019-01-23

Contiki OS BSD MSP430

ARM

AVR

8051 FileSystem

Network

6LoWPAN

Command Line Interface Contiki is an open source operating system for the Internet of Things. Contiki connects tiny low-cost, low-power microcontrollers to the Internet. 3.0 Code

Code Website 2018-11-03

StratifyOS GPL ARM StratifyOS is a powerful embedded RTOS for the ARM Cortex M microcontrollers. v3.7.0 Code

Code Website 2018-09-04

BeRTOS Modified GPL AVR

x86

PowerPC

x86_64 BeRTOS is a real time open source operating system supplied with drivers and libraries designed for the rapid development of embedded software. Code

Code Website 2018-08-09

Xenomai GPL ARM

x86

PowerPC FileSystem

Network

TLS/SSL Xenomai is a real-time development framework cooperating with the Linux kernel, in order to provide a pervasive, interface-agnostic, hard real-time support to user-space applications, seamlessly integrated into the GNU/Linux environment. v3.0.7 Code

Code Website 2018-07-25

cocoOS BSD MSP430

ARM

AVR cocoOS is a free, open source, cooperative task scheduler, based on coroutines targeted for embedded microcontrollers like AVR, MSP430 and STM32. 5.0.1 Website 2018-06-15

BRTOS MIT MSP430

AVR

ColdFire

PIC BRTOS is a lightweight preemptive real time operating system designed for low end microcontrollers. Code

Code Website 2018-03-01

RTEMS GPL ARM

x86

MIPS

PowerPC

m68k FileSystem

Network

TLS/SSL

Command Line Interface RTEMS is an open source RTOS that supports open standard application programming interfaces such as POSIX. It is used in space flight, medical, networking and many more embedded devices. 4.11 Code

Code Website 2018-02-16

RTAI GPL ARM

x86

PowerPC

x86_64

m68k RTAI is the RealTime Application Interface for Linux - which lets you write applications with strict timing constraints for your favourite operating system. The RTAI distribution includes RTAI-Lab, a tool chain to convert block diagrams into RTAI executab RTAI 5.1 Code

Code Website 2018-02-05

LibreRTOS Apache License AVR LibreRTOS is a portable single-stack Real Time Operating System. All tasks share the same stack, allowing a large number or tasks to be created even on architectures with low RAM, such as ATmega328P (2kB). dev-master Code

Code Website 2017-11-15

Atomthreads BSD AVR Atomthreads is a free, lightweight, portable, real-time scheduler for embedded systems. release1.3 Code

Code Website 2017-08-27

uKOS GPL v3 ARM uKOS is a multi-tasking OS suitable for small embedded µController systems. It is based on a preventive multitasking scheduler. 4.0.0 Website 2017-04-26

MOE MIT ARM MOE is an event-driven scheduler system for 8/16/32-bit MCUs. MOE means “Minds Of Embedded system”. V0.1.6 Code

Code Website 2017-04-21

ATK2 Other Nios II The TOPPERS/ATK (Automotive Kernel) is a real-time operating system for automotive system control publicly released by the TOPPERS project. 1.4.2 Code

Code Website 2017-03-24

TNeo Other ARM TNeo is a well-formed and carefully tested preemptive real-time kernel for 16- and 32-bits MCUs. It is compact and fast. v1.08 Code

Code Website 2017-02-25

MaRTE GPL v2 ARM

x86 Network

Logging MaRTE OS is a Hard Real-Time Operating System for embedded applications that follows the Minimal Real-Time POSIX.13 subset. 2.0 Website 2017-02-22

BitThunder GPL v2 ARM A Reliable Real-Time Operating System & Application Framework. stable-0.9.2 Code

Code Website 2017-01-25

TI-RTOS Kernel Other TI-RTOS Kernel (formerly known as SYS/BIOS v3.00.00 Website 2016-07-09

scmRTOS MIT MSP430

AVR scmRTOS is tiny Real-Time Preemptive Operating System intended for use with Single-Chip Microcontrollers. scmRTOS is capable to run on tiny uCs with as small amount of RAM as 512 bytes. The RTOS is written on C++ and supports various platforms. v5.1.0 Code

Code Website 2016-04-19

MARK3 BSD AVR Mark3 is a sophisticated, modern RTOS and application development platform, targeted towards a growing list of today’s most compelling embedded devices. Code

Code Website 2015-03-08

Fusion Embedded RTOS Other ARM

PowerPC The Fusion Embedded RTOS (Real-Time Operating System) from Unicoi Systems is a Real-Time OS designed and optimized for networking and media-centric processors. Website 2015-03-08

Freescale MQX Other ARM

ColdFire The Freescale MQX Real-Time Operating System (RTOS) provides real-time performance within a small, configurable footprint. The RTOS is tightly integrated with the latest 32-bit MCUs and MPUs from Freescale and is provided with commonly used device drivers 4.2.0 Website 2015-03-07

eCos GPL ARM

MIPS

PowerPC eCos is a free open source real-time operating system intended for embedded applications. The highly configurable nature of eCos allows the operating system to be customised to precise application requirements, delivering the best possible run-time perfor Website 2013-08-25

TNKernel GPL MSP430

ColdFire TNKernel is a compact and very fast real-time kernel for the embedded 32/16/8 bits microprocessors. Website 2013-06-06

FunkOS Other MSP430

AVR FunkOS is an RTOS for 8-32 bit MCUs including AVR, MSP430, and Cortex M3. Both C and C++ kernels avaiable. Key features include preemption, periodic events, device drivers, and mutex/semaphores. Includes a variety of graphics and filesystem middleware. Website 2013-04-23

Femto OS GPL AVR Femto OS: RTOS for small MCU’s like AVR. Code

Code Website 2010-04-24

Prex BSD ARM

x86 Prex is an open source, royalty-free, real-time operating system for embedded systems. It is designed and implemented for resource-constrained systems that require predictable timing behavior. The highly portable code of Prex is written in 100% ANSI C bas 0.9.0 Code

Code Website 2009-10-01

uSmartX BSD ARM

AVR uSmartX is a non-preemptive, multitasking, priority based RTOS. 1.34 Code

Code Website 2006-01-14