Processing is a programming language for people who want to create images, animations, and interactions. It’s free (and open source) and you can find out more about it at processing.org
I spent a month last year experimenting with Processing, and had a lot of fun doing so, and I ended the month with a piece I called the Make A Sketch which I debuted at the first Bay View Gallery Night.
So if you’re interested in creating interactive pieces using Processing, I’ll be one of three instructors leading a workshop about it on February 23rd, 2011. There’s more info here.