It's written in our own functional reactive programming library using Haskell! Proudly not using any closed APIs. It used to work with a LeapMotion as well (see Youtube video), but it's USB behaviour is shitty so we dropped that part.
To use the Oculus Rift, run the OpenGL main function, to play it on a screen with a nice drumset, run the SDL main.
Find the code on https://bitbucket.org/turion/jedinight/.