3D objects tumbling about representing CPU load. Many different objects and will select a random object if you click on the dockapp. The ability to zoom in/out and remove the percent label is present as well. wmCube runs on Linux / Solaris / OpenBSD / FreeBSD / NetBSD.
For comments, see the original dockapps.org entry.
A newer version may be available in the Window Maker dockapps git repository:
git clone https://repo.or.cz/dockapps.git