MIDI.js (on github) ties together, and builds upon frameworks that bring MIDI generation to the browser. Combine MIDI.js with jasmid to create a web-radio MIDI stream similar to this demo… or with Three.js, Sparks.js, or GLSL to create Audio/visual experiments. Piano/guitar simulations, Drum machines, MIDI recording, and all kinds of certified funkitude are within your grasps (with a little elbow grease)!
Google Chrome is recommended for best listening experience—it has timing perfection. Firefox and Safari can both perform a bit more like the piano has been drinking, arrr.
Carpe beerum, and commandeer yer own copy!
The Jack the Tunafish artwork was graciously provided by Boni Deal; http://bonideal.com/
View a live demo of the github project; http://mudcu.be/midi-js/
Please report issues and bugs on Github or here, many thanks