Before delving into the Java based applet, be sure to check out this short primer on the heap sort algorithm if you are somewhat unfamiliar with it. You may then wish to first go through the user's guide to learn the applet's interface and how it works. Finally, check out the visualization applet itself to dissect this truly elegent sorting algorithm.
Technical documentation is also available for anyone wanting to see how this applet was designed and implemented in the Java language. From there, the source code is explained.
Mike Copley, UH for ICS 665 (Prof. J. Stelovsky)