It features an AVR ATMega328 just like an Arduino Uno. The Alamode can be programmed with the Arduino IDE on the Raspberry Pi via the Pi's UART serial pins so a USB port doesn't have to be wasted. Here it is atop a Pi in the Adafruit Pi Box (which is in convertible mode with its roof off):
The Alamode's built-in features include a DS3234 Real Time Clock (RTC), micro SD slot (for independent data logging), servo headers and GPS module header:
Arduino shields can also be stacked on top of the Alamode. The Adafruit motor shield was used for a LEGO train demo:
A web interface was running on the Raspberry Pi to allow users to control the train:
The Pi would then sends commands over serial to the Arduino sketch running on the Alamode to control the motor shield. Here's the demo in action:
I really look forward getting my hands on one once they are available!