Zephyr is a fairly new open-source RTOS, developed in a Linux Foundation Project. The members of this project include several renowned semiconductor companies. Zephyr strives for a functional safety certification, which would make it the first open-source RTOS with such a certification.
- Main website: https://www.zephyrproject.org/
- Meta-tool West: https://docs.zephyrproject.org/latest/guides/west/
- Download: https://github.com/zephyrproject-rtos/zephyr
- Documentation: https://docs.zephyrproject.org/latest/