JTreeMap comes with an applet that you can use directly on your site. Use left click to Zoom and right click to see the menu. Here is an example:
Here are the parameters:
<applet archive="./jtreemap-1.1.0.jar"
code="net.sf.jtreemap.swing.example.JTreeMapAppletExample.class"
width="600" height="400">
<param name="dataFile" value="samples/dataDump.xml"/>
<param name="dataFileType" value="xml"/>
</applet>