fsh
An entertaining interactive desktop aquarium
What do you call a fish with no eyes? fsh!
Fsh was created because I wanted fish on my desktop. I have a coworker running Linux, and there's a feature (google freethefish) that lets you have a fish swimming around on your desktop. I'm running Windows, so obviously, if I wanted a fish, I was going to have to do it myself.
Since then, fsh has added a number of features. You can have basic fsh, ninja fsh, invisible ninja fsh, sharks, laser sharks and barracuda. Sharks will eat anything...