A simple 2D Physics engine: I wanted to play with the new HTML5 Canvas element, so I started writing a 2D physics engine. My goal is to be able to write a simple game. It is still very much in the early phases, but it's fun to play with! Click one of the "Setup" buttons, and then click "Start". You can drag the objects with the mouse. This will only work with a HTML5 capable browser such as Chrome or Firefox 3.5 (or later). The collision detection is very basic — too basic in fact. When objects hit each other at too high speed, or too close to corners, they can get stuck to each other. There is no rest detection and no friction.
Anagram: A fancy way to display an anagram.
Polyhedra: A colleague of mine showed me this animated gif of Alexander's Star, and asked me if it was a real object or just a clever illusion. I was planning to make a 3D animation where you could turn the sides of the star, as in the animated gif, but I never got further than a rotating 3D animation. I added the 5 regular polyhedra for comparison; notice how the star is just a deformed version of the icosahedron.
Blob! My latest experiment: Simulating small sticky balls.
Unicode symbols: Handy script if you are looking for an icon — use a unicode symbol instead! Only problem is that the icons may look different on different computers, and may not even be supported on some machines.