Processing is a programming language based on Java that is ideal for making animations. Here's a few I put together, either from scratch or in a couple cases, by modifying examples on the learning processing web site.
You can download the language interface and compiler for free at the official Processing web site.
|Bubble Objects: a group of bubbles rises up, changing color and size and optionally leaving trails|
|Circles: Interactive circles overlap and change size according to the mouse position. Hypnotic!
Madeleine Boinging (gravity simulation): My niece falls from the top and bounces a little less high with each pass, remaining amazingly calm and unharmed on each boing..
Madeleine boinging and flipping: and this time she flips as she bounces.
|Snake on Pink (modified from an example at learningprocessing.com): Interactive control by mouse|
|Spheres: Rows of randomly colored spheres bounce around the screen, leaving trails. Press the mouse to clear and reset the background color.|
|Dynamic Tinkertoys: draw lines like an etch a sketch with simple or dynamic nodes|