Probably the best way to view the panorama is with Internet Explorer.  It should display correctly without having to install plugins.  Other browsers such as Firefox and Netscape may prompt you to install a plugin - this is for the Java Runtime Environment.  If you see a message about allowing ActiveX to run, it is OK to say yes - this will allow a Java script to run (which is how some of these cool features execute).  After the picture loads, operate the panorama by placing the mouse pointer over the picture and dragging it to the right or left (or up and down) - the picture will rotate as you drag it.  You can also zoom in by clicking on the + in the toolbar.  Clicking on the - will allow you to zoom out.  Play around with it and have some fun!