A version of the Nucleus Plus real-time operating system (RTOS) has been released for Renesas Technology's 16-bit H8S/2674R microcontroller. The kernel, which is under 15 kbytes, can be enhanced with the Nucleus Net TCP/IP stack, which is designed for real-time networking. Nucleus Plus is available for $12,495 in source form. It's royalty-free.
Accelerated Technologywww.acceleratedtechnology.com