JuggleMaster is a siteswap animator. A siteswap is a textual representation for patterns one can juggle (using balls, clubs, etc.). JuggleMaster is mainly useful for understanding specific siteswaps by animating them (including multiplexing). Other uses may include watching patterns without understanding the notation behind them.
This package contains the wxWidgets interface and features a lot of builtin patterns available via a menu.
Siteswap FAQ: http://www.juggling.org/help/siteswap/faq.html