This board is as easy to use as an Arduino! Just plug the USB cable from the board to your computer. Update the drivers and you are ready to go. It has a IDE that is based on the Arduino IDE, so if you know how to program the Arduino then you know how to program the CM-900.
The cost is only 20.00 USD which is cheaper than the Arduino.
The cool thing about this board is that you can use the entire line of Robotis Dynamixel servos from the AX-12 to the Dynamixel Pro!
"CM-900 Series is the embedded board with STM32F103C8 based on 32Bit ARM Cortext-M3 and its circuit diagram and the entire sources are open to public."
CM-900 rev. 1.01, a set on Flickr.