RT-Thread

RT-Thread
Developer	Bernard Xiong & RT-Thread Team
Written in	C
Working state	Current
Source model	Open source
Initial release	2006; 18 years ago
Latest release	4.0.3 / December 31, 2020; 3 years ago
Repository	github.com/RT-Thread/rt-thread ;
Marketing target	Embedded systems, IoT
Platforms	ARM (Cortex-M0, -M3, -M4, -M7, -M23, -R4, -A8, -A9; ARM7, ARM9, ARM11), MIPS32, RISC-V, ARC, TMS320 DSP, C-Sky, x86
Kernel type	Monolithic
License	Apache 2.0
Official website	www.rt-thread.io

RT-Thread is an open-source real-time operating system (RTOS) for embedded systems and Internet of things (IoT).^[1]^[2] It is developed by the RT-Thread Development Team based in China. RT-Thread is aimed to change the current situation in China that there is no well used open-source real-time operating system in the microcontroller field.

As of August 2020^[update], RT-Thread was reported to be #3 on the list of RTOSes with the largest number of contributors (behind Zephyr and Mbed).^[3]

Variants

In 2006, RT-Thread began as an open-source real-time operating system (RTOS) that is mainly written in the programming language C. In 2017, a second variant was released for resource-constrained microcontrollers; it needs a minimum of 3 kB flash memory or read-only memory (ROM) and 1.2 kB random-access memory (RAM). Also, RT-Thread's first variant was named Standard, and second variant was named Nano.^[1]^[2]