Window Maker dockapp displaying a bean machine.
From Wikipedia :
The bean machine, also known as the quincunx or Galton box, is a device invented by Sir Francis Galton to demonstrate the central limit theorem, in particular that the normal distribution is approximate to the binomial distribution. Among its applications, it afforded insight into regression to the mean or “regression to mediocrity”.
This dockapp is not maintained by the Window Maker Developers Team. Please visit the dockapp's website for downloads.