Want to see a cool example of real-time control? Check out this video of a QNX-based system controlling a Furuta pendulum:
This isn't just a parlor trick. Furuta pendulums help engineering students learn the principles of controlling dynamic or unstable systems, such as walking robots. In this case, the pendulum was part of a student project at the Norwegian University of Science and Technology.
Remotely related trivia: Josef Hofmann, a piano virtuoso and inventor who lived from 1876 to 1957, is credited with inventing windshield wipers for cars. Story has it, he got the idea by watching a metronome — which, of course, is a pendulum — swinging back and forth. (Metronomes, thankfully, went digital in the 1980s. The older mechanical types had a tendency to beat out syncopated rhythms when placed on anything less than a perfectly flat surface.)