That's my friend Tim with our final project as Clemson EE students back in 2004. We were given a computer running QNX and told to build a pendubot:

The Pendubot is a two-linked inverted pendulum actuated by a single motor. The links are connected to each other by a rotational joint, and the base of one link is connected to the motor. Control of the Pendubot is available only at the base of one of the links, thus the challenge of the project is to balance the top link by only the bottom link.

I recently found this video, and so I thought I'd share by making my first youtube.com upload.