by the numbers
This is an animated tutorial on the Siteswap notational system for juggling patterns, the rec.juggling standard. The thumbnail juggler applets illustrating the text (like the four above) can be linked up with a master juggler; double click on one to send its pattern to the main juggler, where you can play with it!
Single clicking toggles a juggler running or stopped; the thumbnails are for the most part stopped when you first see them, and just show up as black squares, usually captioned with their assigned pattern. Read the "About the animator" page to see the specifications for well-formed juggling patterns.