Juggle Saver is a Windows screensaver that animates juggling patterns in 3D using OpenGL. The program is rather dated and doesn't work terribly well on modern hardware with mutliple monitors.Screensavers are no longer a big thing so the code is unlikely to be updated.
The update using Javascript and WebGL works on most modern browsers and is the best way to see the animation engine at work.
Download: JSInst.exe (98KB).
A port of JuggleSaver was included in the xcreensaver project and this code was in turn incoporated into JuggleMaster.
The source is available on github.