Dave Seidel has released version 4.0 of his Implication Organ instrument.

The Implication Organ is a real-time instrument that runs on a Raspberry Pi, with MIDI input, two- or four-channel audio output, and an OSC interface using a GUI created with Open Stage Control. It is a duophonic instrument (in the sense that a maximum of two simultaneous notes may be played) that generates complex chords based on the frequencies of those notes. For more information, see the GitHub repo for the project.