Pomagma — An Experiment in Extensional Programming — github
Kazoo — Experiments in psychoacoustics and musical instruments — github
The Rational Keyboard — A browser app experiment in just intonation — github
Johann — A toolset for statistical analysis of equations in combinatory algebras — github
Jenn3D — A toy for visualizing 4D Coxeter polytopes via stereographic projection to 3D — github
...more on github...
The Rational Keyboard is an HTML5 web app demonstrating a consonance model in just intonation. It's kind of like a piano with infinitely many keys (one for each rational number) that move around and resize based on what sounds good.