RTOS

• Zephyr - The Zephyr OS is based on a small-footprint kernel designed for use on resource-constrained and embedded systems: from simple embedded environmental sensors and LED wearables to sophisticated embedded controllers, smart watches, and IoT wireless applications.
• RT-Thread - RT-Thread有完整版和Nano版，对于资源受限的微控制器（MCU）系统，可通过简单易用的工具，裁剪出仅需要 3KB Flash、1.2KB RAM 内存资源的 NANO 内核版本；而相对资源丰富的物联网设备，可使用RT-Thread完整版，通过在线的软件包管理工具，配合系统配置工具实现直观快速的模块化裁剪，并且可以无缝地导入丰富的软件功能包，实现类似 Android 的图形界面及触摸滑动效果、智能语音交互效果等复杂功能。
• FreeRTOS - FreeRTOS offers feature stability with long term support (LTS) releases. FreeRTOS LTS libraries come with security updates and critical bug fixes to the FreeRTOS kernel and IoT libraries listed below for two years, and are maintained by AWS for the benefit of the FreeRTOS community. With FreeRTOS LTS, you get a complete set of libraries needed for secure cloud connectivity. Long term support helps reduce maintenance and testing costs associated with updating libraries on your devices already in production.
• amazon-freertos - is an operating system for microcontrollers that makes small, low-power edge devices easy to program, deploy, secure, connect, and manage.
• mbed-os - Arm Mbed OS is an open source embedded operating system designed specifically for the “things” in 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.
• threadx - 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.
• micropython - This is the MicroPython project, which aims to put an implementation of Python 3.x on microcontrollers and small embedded systems.
• uC/OS-II - Official Git repository for the Micrium uC/ products featuring the highly reliable uC/OS-II and III kernels, TCP/IP and USB stacks, as well as the robust uC/FS.
• AliOS-Things - AliOS Things发布于2017年杭州云栖大会， 是 AliOS 家族旗下的、面向IoT领域的、高可伸缩的物联网操作系统，于2017年10月20号宣布在github上开源。
• TencentOS-tiny - TencentOS tiny 是腾讯面向物联网领域开发的实时操作系统，具有低功耗，低资源占用，模块化，安全可靠等特点，可有效提升物联网终端产品开发效率。TencentOS tiny 提供精简的 RTOS 内核，内核组件可裁剪可配置，可快速移植到多种主流 MCU (如 STM32 全系列)及模组芯片上。而且，基于 RTOS 内核提供了丰富的物联网组件，内部集成主流物联网协议栈（如 CoAP/MQTT/TLS/DTLS/LoRaWAN/NB-IoT 等），可助力物联网终端设备及业务快速接入腾讯云物联网平台。
• RIOT - RIOT is developed by an international open source community which is independent of specific vendors (e.g. similarly to the Linux community). RIOT is licensed with LGPLv2.1, a copyleft license which fosters indirect business models around the free open-source software platform provided by RIOT, e.g. it is possible to link closed-source code with the LGPL code.
• Nuttx - Apache NuttX (Incubating) 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. Additional standard APIs from Unix and other common RTOSs (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()).

MISC

• MCUBoot - MCUboot is a secure bootloader for 32-bit MCUs. The goal of MCUboot is to define a common infrastructure for the bootloader, system flash layout on microcontroller systems, and to provide a secure bootloader that enables simple software upgrades.
• cJSON - Ultralightweight JSON parser in ANSI C.
• mbedtls - Mbed TLS is a C library that implements cryptographic primitives, X.509 certificate manipulation and the SSL/TLS and DTLS protocols. Its small code footprint makes it suitable for embedded systems.
• GoogleAuthentificatorC - The Google Authenticator project includes implementations of one-time passcode generators for several mobile platforms.
• pre-commit-hooks
  • This is a pre-commit hooks repo that integrates two C/C++ code formatters:
    • clang-format
    • uncrustify
  • and five C/C++ static code analyzers:
    • clang-tidy
    • cppcheck
    • oclint
    • cpplint
    • include-what-you-use