This remains a beta version; the correctness of the implementation has not been tested.
A Java window should pop up on your screen if Java is enabled. It will disappear if you hit "BACK" in your web browser.
Example:
File -> Load Example -> Sierpinski
Controls -> Run
(right-click in the lower left corner) -> Tile 7
[note: works on Linux. How to right-click on Mac OS X?]
Instructions for other menu options will be coming...