An processing implementation of Maciej Matyka's soft body tutorial paper. Here is what it looks like:
Note: The original code was written in Java while I was in high school and is included for the sake of completeness. Back then I didn't know what I was doing (nor do I now), which is the reason for the single source file, default package, magic numbers, and generally awful code. The processing port (which is what runs in the browser if you click the link above) is marginally cleaner.
Code is released under the FreeBSD / simplified BSD license.