The hardware is http://www.makeblock.cc/xy-plotter-robot-kit/ sans electronics. I ended up purchasing the electronics anyways because they have a modified Arduino that uses RJ25, which makes the wiring much more stable (as opposed to pins stuck into an Arduino).

If you got the individual pieces yourself or 3D printed it can be much cheaper.

The main electrical components are:

1 x Arduino Uno (I used the modified Uno called "Orion" that has RJ2 ports) 2 x Stepper motors 1 x Servo motor 4 x microswitches as limit switches 2 x stepper motor drivers (they handle the microstepping) 3 x RJ25 breakout boards (for connecting the limit switches to RJ25 ports)

This was a prototype to prove the concept. I'm going to experiment with 3D printed parts next in a new design.

If you're feeding in coordinates as Gcode I would recommend loading Grbl. Keep in mind Grbl has specific pin requirements that make it incompatible with the Orion's RJ25 ports, so you'd have to wire a normal Arduino. Makeblock supplies Gcode firmware that works with the Orion.

For the demo in the video, the firmware was custom to handle real-time input and recording of motion.

On the host computer side, it was just a python script that interfaced with the Wacom tablet. Specifically: https://bitbucket.org/AnomalousUnderdog/pythonmactabletlib

I also hacked support for the Myo armband and mouse support.