* [libmemory](https://github.com/embeddedartistry/libmemory) - Memory management library with implementations for malloc(), free(), and other useful memory management functions.
* [lwmem](https://github.com/MaJerle/lwmem) - Lightweight dynamic memory manager library for embedded systems with memory constraints. It implements malloc, calloc, realloc and free functions.
* [EmbeddedProto](https://github.com/Embedded-AMS/EmbeddedProto) - C++ Protocol Buffers implementation specifically suitable for ARM Cortex-M microcontrollers. It is small, reliable and easy to use.
* [protobuf-embedded-c](https://github.com/berezovskyi/protobuf-embedded-c) - Protocol buffers generator for resource constrained embedded applications written in the C programming language.
* [fat32](https://github.com/strawberryhacker/fat32) - Lighweight FAT32 file system written in C with no thirdparty dependencies. It requires a small port which provide functions for initializing, reading and writing to the MSD.
* [emfat](https://github.com/fetisov/emfat) - FAT32 emulation library for stm32f4.
* [interchange](https://github.com/trussed-dev/interchange) - Request/response mechanism for embedded development, using atomics.
* [xmodem](https://github.com/bsail/xmodem) - XMODEM Library for embedded, mobile, iot, and desktop systems.
* [microrl](https://github.com/Helius/microrl) - Micro read line library for small and embedded devices with basic VT100 support.
* [TinyFrame](https://github.com/MightyPork/TinyFrame) - Simple library for building and parsing data frames for serial interfaces (like UART / RS232).
* [RadioHead](https://github.com/hallard/RadioHead) - Packet Radio library for embedded microprocessors.
* [Adafruit's RadioHead](https://github.com/adafruit/RadioHead) - Packet Radio library for embedded microprocessors with [docs](http://www.airspayce.com/mikem/arduino/RadioHead/).
* [uIP](https://github.com/adamdunkels/uip) - Very small implementation of the TCP/IP stack that is written by Adam Dunkels.
* [LwIP](http://savannah.nongnu.org/projects/lwip/) - Small independent implementation of the TCP/IP protocol suite that has been initially developed by Adam Dunkels. lwIP suitable for use in embedded systems with tens of kilobytes of free RAM and room for around 40 kilobytes of code ROM.
* [mongoose](https://github.com/cesanta/mongoose) - Embedded Web Server and Embedded Networking Library. It implements event-driven non-blocking APIs for TCP, UDP, HTTP, WebSocket, MQTT.
* [libevhtp](https://github.com/criticalstack/libevhtp) - Extremely-fast and secure embedded HTTP servers with ease.
* [libμhttpd](https://github.com/zhaojh329/libuhttpd) - Very flexible, lightweight and fully asynchronous HTTP server library based on libev and http-parser.
* [LwGPS](https://github.com/MaJerle/lwgps) - Lightweight GPS NMEA parser for embedded systems.
* [LwESP](https://github.com/MaJerle/lwesp) - Lightweight ESP AT commands parser library to communicate with ESP8266 or ESP32 Wi-Fi module using AT commands.
* [LwGSM](https://github.com/MaJerle/lwgsm) - Library for SIMCOM GSM modules to communicate with AT commands and RTOS from host device.
* [GSM_Engine](https://github.com/MikroElektronika/GSM_Engine) - Generic AT parser for AT command based modules.
* [TinyGSM](https://github.com/vshymanskyy/TinyGSM) - Small Arduino library for GSM modules, that just works.
* [liquid-dsp](https://github.com/jgaeddert/liquid-dsp) - Digital signal processing library for software-defined radios.
* [minfft](https://github.com/aimukhin/minfft) - Small and fast Discrete Fourier Transform library.
* [iir1](https://github.com/berndporr/iir1) - DSP IIR realtime filter library written in C++.
* [kalman-clib](https://github.com/sunsided/kalman-clib) - Microcontroller targeted naive Kalman filter implementation in pure C.
* [libdspl](https://sourceforge.net/p/libdspl-2-0/code/ci/master/tree/) - Cross-platform digital signal processing algorithm library, written in C language.
* [heatshrink](https://github.com/atomicobject/heatshrink) - Data compression library for embedded/real-time systems.
* [shoco](https://github.com/Ed-von-Schleck/shoco) - C library to compress and decompress short strings. It is very fast and easy to use. The default compression model is optimized for english words, but you can generate your own compression model.
* [ECL](https://github.com/Nonoum/ECL) - Embedded Compression Library is not only for embedded, it is mostly oriented for small data and has special optimized low-memory modes for restricted environments.
* [Cranium](https://github.com/100/Cranium) - Portable, header-only, feedforward artificial neural network library written in vanilla C99.
* [μTensor](https://github.com/uTensor/uTensor) - TinyML AI inference library.
* [Fido](https://github.com/FidoProject/Fido) - Lightweight C++ machine learning library for embedded electronics and robotics.
* [nnom](https://github.com/majianjia/nnom) - Neural Network on Microcontroller (NNoM) is a high-level inference Neural Network library specifically for microcontrollers.
* [caffepresso](https://github.com/gplhegde/caffepresso) - Optimized Library for Deep Learning on Embedded Accelerator-based platforms.
* [libonnx](https://github.com/xboot/libonnx) - Lightweight, portable pure C99 onnx inference engine for embedded devices with hardware acceleration support.
* [trussed](https://github.com/trussed-dev/trussed) - Minimal, modular way to write cryptographic applications on microcontroller platforms (Rust).
* [wolfSSH](https://www.wolfssl.com/products/wolfssh/) - Lightweight SSHv2 client and server library written in ANSI C and targeted for embedded, RTOS, and resource-constrained environments - primarily because of its small size, speed, and feature set.
* [mbedTLS](https://github.com/Mbed-TLS/mbedtls) - Open source, portable, easy to use, readable and flexible TLS library, and reference implementation of the PSA Cryptography API.
* 🔝[liblithium](https://github.com/teslamotors/liblithium) - Lightweight cryptography library that is portable by design. It requires only standard C99 and does not assume 8-bit addressability, making it suitable for use on some DSP architectures as well as mainstream architectures.
* 🔝[trezor-crypto](https://github.com/trezor/trezor-firmware/tree/master/crypto) - Heavily optimized cryptography algorithms for embedded Devices.
* [poly1305-donna](https://github.com/floodyberry/poly1305-donna) - Implementations of a fast Message-Authentication Code (8 bit, 16 bit, 32 bit and 64 bit multiplies versions).
* [pcg-c-basic](https://github.com/imneme/pcg-c-basic) - Code provides a minimal implementation of one member of the PCG family of random number generators, which are fast, statistically excellent, and offer a number of useful features.
* [pcg-c](https://github.com/imneme/pcg-c) - Code provides an implementation of the PCG family of random number generators, which are fast, statistically excellent, and offer a number of useful features.
* [citrus](https://github.com/strawberryhacker/citrus) - Bare metal ARM® Cortex®-A5 operating system.
* [vanilla](https://github.com/strawberryhacker/vanilla) - Bare metal ARM® Cortex®-M7 operating system.
* 🔝[chaos](https://github.com/strawberryhacker/chaos) - Bare metal multicore ARM® Cortex®-A operating system based on a microkernel architecture.
* [LK kernel](https://github.com/littlekernel/lk) - The Little Kernel Embedded Operating System is SMP-aware kernel designed for small systems ported to a variety of platforms and cpu architectures.
* [QuarkTS](https://github.com/kmilo17pet/QuarkTS) - OS for embedded applications that supports prioritized cooperative scheduling, time control, inter-task communications primitives, hierarchical state machines and CoRoutines.
* [Zephyr](https://github.com/zephyrproject-rtos/zephyr) - New generation, scalable, optimized, secure RTOS for multiple hardware architectures.
* [Apache NuttX](https://github.com/apache/incubator-nuttx) - Apache NuttX is a mature, real-time embedded operating system (RTOS).
* [scmRTOS](https://github.com/scmrtos/scmrtos) - 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.
* [ChibiOS/RT](https://github.com/ChibiOS/ChibiOS) - Compact and fast real-time operating system supporting multiple architectures designed for embedded applications on microcontrollers of 8-, 16-, and 32-bits.
* [Azure RTOS ThreadX](https://github.com/azure-rtos/threadx) - Advanced real-time operating system (RTOS) designed specifically for deeply embedded applications.
* [eCos](https://ecos.sourceware.org/) - Real-time operating system intended for embedded applications _(Closed source)_.
* [embox](https://github.com/embox/embox) - Configurable RTOS designed for resource constrained and embedded systems. Embox main idea is using Linux software without Linux.
* [RIOT](https://github.com/RIOT-OS/RIOT) - 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. RIOT is based on the following design principles: energy-efficiency, real-time capabilities, small memory footprint, modularity, and uniform API access, independent of the underlying hardware (this API offers partial POSIX compliance).
* [Arm Mbed OS](https://github.com/ARMmbed/mbed-os) - Platform operating system designed for the Internet of Things. It includes all the features you need to develop a connected product based on an Arm Cortex-M microcontroller, including security, connectivity, an RTOS and drivers for sensors and I/O devices.
* [RT-Thread](https://github.com/RT-Thread/rt-thread) - RT-Thread was born in 2006, it is an open source, neutral, and community-based real-time operating system (RTOS). RT-Thread has Standard version and Nano version. For resource-constrained microcontroller (MCU) systems, the NANO kernel version that requires only 3KB Flash and 1.2KB RAM memory resources can be tailored with easy-to-use tools; And for resource-rich IoT devices, RT-Thread can use the on-line software package management tool, together with system configuration tools, to achieve intuitive and rapid modular cutting, seamlessly import rich software packages, thus achieving complex functions like Android's graphical interface and touch sliding effects, smart voice interaction effects, and so on.
* [distortos](https://github.com/DISTORTEC/distortos) - Object-oriented C++ RTOS for microcontrollers.
* [R3-OS](https://github.com/r3-os/r3) - Experimental static (μITRON-esque) RTOS for deeply embedded systems, testing the limit of Rust's const eval and generics _(Rust)_.
* [Tock Embedded OS](https://github.com/tock/tock) - Embedded operating system designed for running multiple concurrent, mutually distrustful applications on low-memory and low-power microcontrollers _(Rust)_.
* [dandelion](https://github.com/AntoineSebert/dandelion) - Microkernel Real-Time Operating System in Rust.
* [MuditaOS](https://github.com/mudita/MuditaOS) - Mobile operating system based on FreeRTOS optimized for E Ink displays - developed for Mudita Pure minimalist phone.
* [cli](https://github.com/letgo0007/cli) - CLI (Command Line Interface) example build in pure C. Designed for MCU, support block/non-block mode input.
* [terminal](https://github.com/JingoC/terminal) - Command Line Interface for microcontrollers. Flexible terminal settings allow you to integrate it with any microcontroller, without much effort.
* [SerialMenu](https://github.com/sonyhome/SerialMenu) - Arduino library to easily create menus on the serial console.
* [ProMenu](https://github.com/marcinbor85/ProMenu) - Advanced Generic Application Menu Library. ProMenu Library is used for fast implementing advanced user menus. It supports nesting, numeric settings, text settings, boolean values and events. Library is implemented in C++ with build-in Arduino port, but it is easy to port to different architecture.
* [lwprintf](https://github.com/MaJerle/lwprintf) - Lightweight printf library optimized for embedded systems.
* [Embedded_Printf](https://github.com/agaelema/Embedded_Printf) - Embedded version of the famous "printf( )" function. The idea is create an simple and efficient library to meet some common needs in embedded systems.
* [tinyprintf](https://github.com/cjlano/tinyprintf) - Tiny printf and sprintf library for small embedded systems.
* [trice](https://github.com/rokath/trice) - Super fast and tiny embedded device C printf-like trace code (works also inside interrupts) and real-time PC logging (trace ID visualization).
* [embedded-diagnostic-logger](https://github.com/binarymaker/embedded-diagnostic-logger) - Lightweight logger framework for small microcontroller based projects. Multilevel log and token based string transfer.
* [TouchGFX](https://www.touchgfx.com/product/overview/) - User-friendly graphical C++ tool integrated as a free tool in the STM32 ecosystem.
* [eGUI](https://github.com/NXPmicro/eGUI) - An eGUI embedded graphic library.
* [Embedded-graphics](https://github.com/embedded-graphics/embedded-graphics) - 2D graphics library that is focused on memory constrained embedded devices.
* [SGFX](https://github.com/rprata/sgfx) - Lightweight embedded library for displays and touchscreens providing everything required to build a fully featured embedded GUI.
* [GUIX](https://github.com/azure-rtos/guix) - Provides a complete, embedded graphical user interface (GUI) library and design environment, facilitating the creation and maintenance of all graphical elements needed by your device.
* [ttf2mesh](https://github.com/fetisov/ttf2mesh) - Library for TrueType font tessellation. Allows to convert font glyphs to mesh objects without rasterization.
* [lcd-image-converter](https://github.com/riuson/lcd-image-converter) - Tool to create bitmaps and fonts for embedded applications; allows you to create bitmaps and fonts, and transform them to "C" source format for embedded applications.
* [libcanard](https://github.com/UAVCAN/libcanard) - Compact implementation of the UAVCAN/CAN protocol in C for high-integrity real-time embedded systems.
* [C-Thread-Pool](https://github.com/Pithikos/C-Thread-Pool) - Minimal but powerful thread pool in ANSI C.
### Firmware updates
* [SWupdate](https://github.com/sbabic/swupdate) - Software Update for Embedded Linux Devices to update system in field. SWUpdate supports local and OTA updates, multiple update strategies and it is designed with security in mind.
* [Apache NuttX Apps](https://github.com/apache/incubator-nuttx-apps) - Collection of tools, shells, network utilities, libraries, interpreters and can be used with the NuttX RTOS.
