AO RTOS is small real time OS based on Active Object concurrency model
RTOS for Secure, Safe and Real-Time Systems
Real-Time Embedded Operating System
Mulithreading Arduno library
Embedded Real-Time Operating System (RTOS)
Custom firmware and IDE for the VEX Cortex Microcontroller
Yet another Kernel - clone the git repo for newest version
Hard Real-Time OS compliant to the Osek/Vdx standard.
Mayax is a 32-bit hobby OS with windows style GUI.
A rethinking of the Operating System Ecosystem.