The classic RPL programming language reimplemented and reimagined.
It's a personal microkernel project designed as a learning ground.
Hobby operating system, bootloader, kernel, drivers, C library
Real time preemptive embedded multi-thread kernel
Open-source RTOS and Embedded Systems Toolkit for C++ and C
Hanthana Linux Project
A UNIX-like kernel for the i386 architecture
High level interface to the Linux Kernel's seccomp filter