You most certainly know about Twitter Bootstrap - the popular front end framework for building websites and apps. It favors simple, responsive design, and comes bundled with a sensible default stylesheet, a number of useful jQuery plugins ...
A simple particle system physics engine for processing. I've designed this to be application / domain agnostic. All this is supposed to do is let you make particles, apply forces and calculate the positions of particles over time in real-time. Anything else you need to handle yourself.