Open Panzer is a community project developing Open Source hardware and software for the RC tanks:
Open Panzer TCB (Tank Control Board): highly-capable and very flexible control board designed specifically for RC model tanks, but also suitable for halftracks, cars, or even battleships.
The hardware is based on an ATmega 2560 processor and the firmware consists of an Arduino sketch as well as various C++ libraries.
The hardware design files are available on the Open Panzer Downloads page:
OpenPanzer has shared several boards on OSH Park including: