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Open Source Real-Time Operating Systems

Discover the best Open Source RTOS solutions for embedded systems and IoT devices

Featured Projects

Giulia TFT

An ESP32-based telemetry display for Alfa Romeo Giulia and Stelvio JTDm vehicles. It interfaces with a Bluetooth OBD2 adapter to monitor engine parameters, DPF regeneration cycles, and battery health using the LVGL graphics library on a touchscreen TFT display.

lvgltft-espi

TOTEMX Split Keyboard

A 38-key column-staggered split keyboard designed for Cherry MX spacing. It supports Seeed Studio XIAO RP2040 or nRF52840 microcontrollers and is a replica of the original TOTEM keyboard design adapted for 19.05x19.05mm switch spacing.

zephyr

pigg: Raspberry Pi and Pi Pico GPIO Remote Control

A comprehensive suite of applications for remote GPIO control and visualization on Raspberry Pi and Pi Pico hardware. It features a cross-platform GUI for real-time monitoring and configuration, a headless CLI agent for remote execution, and specialized embedded firmware for Pi Pico microcontrollers.

383

esp-lvgl

A comprehensive collection of LVGL (Light and Versatile Graphics Library) examples and tutorials for ESP32 and ESP8266 platforms. It supports multiple development frameworks including Arduino, ESP-IDF, and MicroPython, providing drivers and UI templates for various display types.

freertos lvgltft-espimicropython

ESP8266/ESP32 Spotify OLED Display

An Arduino-based project for ESP8266 and ESP32 that displays live Spotify playback details and weather information on an SH1106 OLED screen. It features real-time track synchronization, progress bars, and an idle mode showing time and temperature using the OpenWeatherMap API.

Acid Drop: Custom Firmware for LilyGo T-Deck

A custom firmware for the LilyGo T-Deck handheld device, featuring a graphical IRC client built with LVGL. It supports WiFi connectivity, audio playback, and various command-and-control features on the ESP32-S3 platform.

freertos lvgllwipplatformio-platformio-core

142

Mercury Transforming Drone

Mercury is a multi-modal transforming drone platform that combines aerial flight and ground-based driving capabilities. It utilizes a Raspberry Pi 5 for high-level autonomy and an ArduPilot-based flight controller for stable dynamics, featuring a unique transformation mechanism powered by linear actuators.

chibios-rt

OBD2 to MQTT for Home Assistant

An ESP32-based firmware that extracts vehicle data via an ELM327 OBD2 adapter and transmits it to an MQTT broker over cellular networks. Designed for Home Assistant integration, it supports a wide range of LilyGO T-Call and Waveshare modules with integrated GSM/LTE and GPS capabilities.

freertos littlefsnimbleh2zero-esp-nimble-cpp

198

Latest RTOS

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ChibiOS/RT

ver21.11.4

ChibiOS is a modular, high-performance development environment for embedded systems, featuring a dual-kernel architecture with the full-featured RT kernel and the ultra-compact NIL kernel. It provides a comprehensive Hardware Abstraction Layer (HAL), a Virtual File System (VFS), and advanced sandboxing capabilities, making it highly suitable for functional safety and multicore ARM Cortex-M applications.

827 Updated: 3/8/2026

ARMARM Cortex-MARM Cortex-AARM Cortex-RARM7ARM9ARM11POSIX

GPL-3.0

Hubris

all-sp-v1.0.63

Hubris is a memory-isolated, task-based RTOS written in Rust, specifically designed for deeply-embedded microcontrollers with high reliability requirements. It eliminates dynamic resource allocation and runtime task creation to minimize attack surfaces and ensure deterministic behavior in critical systems.

3,451 Updated: 3/7/2026

ARMARM Cortex-MLinuxWindowsmacOSPOSIX

MPL-2.0

NuttX

nuttx-12.12.0

Apache NuttX is a highly scalable, standards-compliant real-time operating system (RTOS) designed for deeply embedded environments ranging from 8-bit to 64-bit architectures. It distinguishes itself by strictly adhering to POSIX and ANSI standards, providing a familiar Unix-like programming interface while maintaining a minimal footprint and modular architecture.

3,727 Updated: 3/6/2026

ARMARM Cortex-MARM Cortex-AARM Cortex-RARM7ARM9AArch32AArch64 +22 more

Apache-2.0

RIOT

2026.01

RIOT is a modular, open-source real-time operating system specifically engineered for the Internet of Things (IoT), supporting a wide range of 8-bit, 16-bit, and 32-bit microcontrollers. It features a micro-kernel architecture with a preemptive, tickless scheduler and provides a uniform API with partial POSIX compliance to simplify cross-platform development and code reuse.

5,690 Updated: 3/6/2026

ARMARM Cortex-MARM7RISC-VXtensaAVRMSP430Linux +7 more

LGPL-2.1

Eclipse ThreadX

v6.5.0.202601_rel

Eclipse ThreadX is an industrial-grade real-time operating system (RTOS) featuring a non-layered picokernel architecture designed for deeply embedded, resource-constrained IoT applications. It provides deterministic scheduling, advanced multicore support through Symmetric Multiprocessing (SMP), and optional memory protection via a modular deployment system.

3,376 Updated: 3/6/2026

ARM Cortex-MARM Cortex-AARM Cortex-RRISC-VXtensaMIPSRXArc +15 more

MIT

TizenRT

3.0_GBM

TizenRT is a lightweight, RTOS-based platform designed for low-end IoT devices with limited resources, typically equipped with ARM Cortex-M/R processors and less than 2MB of RAM. It extends the NuttX kernel with a comprehensive ecosystem including Linux-style development environments, advanced networking stacks, and support for high-level languages like JavaScript to bridge the gap between RTOS efficiency and Linux-like developer experience.

643 Updated: 3/6/2026

ARM Cortex-MARM Cortex-RXtensaQEMUAArch32

Apache-2.0

Phoenix-RTOS

v3.3.2

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

158 Updated: 3/5/2026

ARMx86RISC-V

BSD

embox

v0.7.0

Embox is a highly modular and configurable real-time operating system designed to execute Linux-compatible software on resource-constrained embedded systems and microcontrollers. It provides a POSIX-compliant environment, allowing developers to port complex desktop-grade libraries and applications like Qt, OpenCV, and PJSIP to platforms with limited RAM and ROM.

1,546 Updated: 3/4/2026

ARMARM Cortex-MARM Cortex-Ax86RISC-VMIPSSPARCPowerPC +8 more

BSD

Latest Libraries

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Open Thread

thread-reference-20250612

OpenThread is an open-source, OS-agnostic implementation of the Thread networking protocol designed for low-power wireless mesh networking in home and commercial automation. It features a highly portable architecture with a narrow platform abstraction layer, supporting System-on-Chip (SoC), Network Co-Processor (NCP), and Radio Co-Processor (RCP) designs while maintaining a small memory footprint.

3,903 Updated: 3/8/2026

BSD 3-Clause

Wireless

sqlite

vesion-3.45.1

SQLite is a C-language library that implements a small, fast, self-contained, high-reliability, and full-featured SQL database engine. It functions as a serverless, zero-configuration database that compiles SQL statements into bytecode for execution on a custom virtual machine, making it the most widely deployed database engine in the world.

9,140 Updated: 3/8/2026

Public Domain

Database

u8g2

2.29.11

U8g2 is a comprehensive monochrome graphics library for embedded systems, designed to support a vast array of OLED and LCD controllers. It provides a flexible dual-library approach, offering U8g2 for full graphical rendering and font support, and U8x8 for memory-efficient, direct-to-display text output.

6,308 Updated: 3/8/2026

Unknown

Graphics

levelx

v6.5.0.202601_rel

LevelX is a specialized flash wear leveling library for embedded systems, providing management for both NAND and NOR flash memory. It presents a logical sector interface to applications while transparently managing physical flash constraints, ensuring even distribution of erase cycles and robust fault tolerance during power interruptions.

146 Updated: 3/6/2026

MIT

FileSystem

Eclipse ThreadX FileX

v6.5.0.202601_rel

Eclipse ThreadX FileX is a high-performance, FAT-compatible file system designed specifically for deeply embedded applications requiring a small memory footprint and high execution speed. It supports FAT12, FAT16, FAT32, and exFAT formats and is fully integrated with the ThreadX RTOS to provide deterministic file management across various physical media including RAM, SD cards, and flash memory.

60 Updated: 3/6/2026

MIT

FileSystem

Eclipse ThreadX GUIX

v6.5.0.202601_rel

Eclipse ThreadX GUIX is a high-performance, small-footprint graphical user interface framework specifically engineered for deeply embedded systems. It provides a comprehensive API for UI development and integrates with GUIX Studio, a desktop design tool that automates C code generation for graphical elements, ensuring rapid development and deployment on resource-constrained hardware.

399 Updated: 3/6/2026

MIT

GUI

LVGL

v9.5.0

LVGL is a lightweight, open-source C graphics library designed to build professional user interfaces on any microcontroller or microprocessor. It features a hardware-independent architecture with low memory requirements, supporting advanced rendering features like anti-aliasing, animations, and complex layout engines.

22,909 Updated: 3/6/2026

MIT

GUI

Tensorflow Micro

v2.21.0

TensorFlow is an end-to-end open-source platform for machine learning that provides a comprehensive ecosystem of tools, libraries, and community resources for both research and production. It features a flexible architecture allowing for seamless deployment across diverse hardware including CPUs, GPUs, and TPUs, while offering stable APIs in Python and C++ alongside a rich set of specialized extensions.

194,038 Updated: 3/6/2026

Apache-2.0

MachineLearning