As part of Play for X, I made a javascript-powered clone of DDR, using SVG. I like working with SVG and javascript - I can directly manipulate drawing rules and maintain an incredibly tight feedback loop as I develop. In this case, though, I was so proud of what I made that I kept trying to make it better. It's far from finished and I've set it aside as I work on other projects, but, in theory, this project was to make a simple javascript clone of DDR - but using the web audio API, I was going to make it so you could load in a file, entirely locally, and it would do automatic beat detection and generate an actual track for your song. Unfortunately, audio processing and beat detection is less than easy and simple when you're using javascript. It's a cool project, and I'm interested in returning to it sometime.