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.
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.