There are four main components:
1. The control board (that I'm making myself)
2. A Tamiya tank chassis and gearbox
3. A raspberry Pi with web server and fcgi API
1. The control board
Going on Version 7 (Minified3).
MCU used is AT32UC3L0.
Using separate battery packs for motors and everything else. Motors need 6V (4 x AA). Everything else uses 12V (8 x AA).
A basic Tamiya model. But was fitted with 6V motors with 800mA stall current (each). You can find those from Adafruit. The smaller current apparently keeps any radio interference to a minimum too.
Notice that I used two chassis kits. Not enough plastic sheets in just one.
3. Raspberry Pi
I used the fcgi-lib to write a minimal RESTful API. Also a minimal web-page to control the contraption.
Server back-end is Nginx, because it was the first one I found clear fcgi-usage instructions for.
Physical layer is a Wi-Fi dongle. I'll try and put the RasPi in access point mode, so that only a laptop will be needed for remote control. For now, it needs a separate access point.
Sources and licencing:
All code (and instructions) is in GitHub. See the README in there.
License on all of my code is GPLv2, i.e. open software.
Other licenses that may apply have to do with the Atmel driver libraries for the MCU, but I'm rather confident that those're open for everyone to see and freely (re-)distributable.