Universal server
Alternative operating system for x86 computers
TTF-GDOS is an Atari GDOS replacement that uses true type fonts
Building and running ancient Linux on Windows
Simplest kernel for cooperative multithreading
RTOS for Secure, Safe and Real-Time Systems
Real time preemptive embedded multi-thread kernel
Real-Time Embedded Operating System
Helps you to Boot your Experimental Assembly Language programs
A UNIX-like kernel for the i386 architecture
Mulithreading Arduno library
AO RTOS is small real time OS based on Active Object concurrency model
A small operating system, compatible with MS-DOS, written in assemly
Embedded Real-Time Operating System (RTOS)
A low-power ISA design and simulator for a 2010 IEEE competition
Small 32-bits operating system
Operating System in 512bytes.