Характеристики RTOS:

http://www.emcu.it/STM32/RTOS-TCPIP-...m-USB-etc.html

Free RTOS for STM32F103
http://www.emcu.it/STM32/RTOS-TCPIP-...m-USB-etc.html

NicheLite TCP/IP stack
http://www.iniche.com/st_lite.php