Zephyr is a small real-time operating system for connected, resource-constrained devices supporting multiple architectures and released under the Apache License 2.0 backed by the Linux Foundation.
- - Zephyr is the most popular Windows, Mac & Linux alternative to FreeRTOS.
- - Zephyr is the most popular Open Source & free alternative to FreeRTOS.
NuttX 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.
embedded Operating System (embOS), is a Real-time operating system, developed by the Company SEGGER Microcontroller. It's designed to be used as a foundation for the development of embedded real-time applications for a wide range of µc.