Need a real-time operating system for your robot that's smaller than Real Time Linux or eCos but want to stick with software that protects your freedoms? An OS News article suggests FreeRTOS, a small OS that includes a real time kernel and scheduler. Ports are available for the Philips ARM7, TI MSP430, Renesas (Hitachi) H8/S, Atmel AVR, Motorola/Freescale HCS12, Motorola/Freescale ColdFire, and others. Lots of documentation and demo programs are available on the FreeRTOS website. FreeRTOS is Free Software licensed under the GNU GPL.