OS-9
A real-time operating system written by Microware Corporation. The original version was written about 1978 for the Motorola 6809 and has since been ported to the Motorola 68000, Intel 80386, Intel 486, and the PowerPC. The kernel of OS-9 is ROMable, modular, with a unified file system, allowing it to easily be scaled up or down as required.
FAQ.