Arduino board support for CrapLab development boards, which at this point is limited to RUDY.
Allows you to add RUDY as 3rd party board to the Arduino IDE via its Board Manager and program it like any other Arduino device - it is after all just an ATmega328 device like the Arduino UNO. There are however two differences: RUDY is clocked at 12MHz instead of the usual 16MHz, and it's a simple, no frills development board, so there is no UART on board and therefore requires an external programmer to upload the Arduino sketch.
Note that this is generally a very hackish approach, and this is a "Arduino can be used on the device as well" rather than a "the device is specifically meant for Arduino" situation.
Adding a 3rd party board package is a quite straightforward process, and I would practically end up copying already existing instructions here - so instead I will just link to the ones from Adafruit.
The Additional Boards Manager URL in this case is:
https://raw.githubusercontent.com/sgreg/craplab-arduino/master/package_craplab_index.json
and the board package will show up as CrapLab Development Boards
