AO RTOS is small real time OS based on Active Object concurrency model
Thread Scheduler with custom asynchronous messaging in VC++
freeRTOS for Arduino Uno, Goldilocks 1284p & Mega 2560
Linux kernel driver for Xbox One and Xbox Series X|S accessories
The smallest and the most powerful operating system.
Open-source RTOS and Embedded Systems Toolkit for C++ and C
A Debug style tool for OS Free systems
Nanux Kernel
SuperWikia: The Runtime/Realtime Environment for Codesmiths