zephyrproject-rtos/zephyrPrimary Git Repository for the Zephyr Project. Zephyr is a new generation, scalable, optimized, secure RTOS for multiple hardware architectures.
Books
The Complete Edition – Software Engineering for Real-Time Systems. A software engineering perspective toward designing real-time systems by Jim Cooling
Rational Rhapsody. a modeling environment based on UML, is a visual development environment for systems engineers and software developers creating real-time or embedded systems and software.
FreeRTOSis a real-time operating system kernel for embedded devices that has been ported to 35 microcontroller platforms.