Using a chip that’s sort of an Arduino times 4, the Reprap team has a new prototype motherboard. Via hackaday:
When the RepRap team found themselves pushing the limits of the Arduino, they started looking for alternatives. They found it in the ATMega644P. It has four times the memory and four times the RAM compared to the ATMega168 used in the standard Arduino. It also has 32 I/O pins… this board has onboard connectors for all of the RepRap’s motors… The goal is to eventually have a board that can run the RepRap without a host computer if necessary; it will manufacture designs directly from the flash card.