Ahm, ok. But Arduino Uno uses ATmega8U2, that has an internal usb-to-ttl serial converter. Riduino uses an ATmega8L (I think it's like atmega8), that don't have this internal converter. The ATmega8U2 is harder to found here in my region. Riduino is an interesting option to test and use. The project is just a mixing of the avrcdc project (http://www.recursion.jp/avrcdc/) and Arduino? If it is, i will try to test this option.