I'd recommend the video for anyone as confused as I was about what this looks like in application: https://www.youtube.com/watch?v=ncfZWqPm7-4
I thought you'd link to the one by Steve Mould, who implemented a snake game on it https://www.youtube.com/watch?v=rf-efIZI_Dg
That one was way better, I just hadn't seen it linked from the official page.
This is open source under GPL3 [1]. It's pretty cool that the infrastructure to design and build basic machines like this is more and more easily available. As far as I can see all the designs can be viewed/edited via open source tools.
Basic bundle: 1205 euro.