A tapas/topaz/sapphire kernel optimized for smoothness and low-memory
amforth is an extendible interpreter on microcontrollers
Software development for 4Mb portable, using Z80 CPU and AA batteries
A cute and educational x86 OS
OS-9/6809 compatible operating system for Tandy CoCo and Dragon
Indipendent distro uses inary package system. Sulin is roolling donkey
Simplest kernel for cooperative multithreading
RTOS for Secure, Safe and Real-Time Systems
Real-Time Embedded Operating System
FreeDOS is an open source DOS-compatible operating system
Run Linux on the Playstation 2
FreeMiNT is a free alternative OS kernel for Atari systems & clones
Run Linux on Windows or other OSes, natively.
A advanced graphical operating system.
Embedded Operating System
An open source OS written in assembly.
A small operating system, compatible with MS-DOS, written in assemly
Embedded Real-Time Operating System (RTOS)
Crosos is a SubLinux Distribution