Can anyone tell me the functionality behind the panoramic views on this page?
but it requires some kind of plugin to work, and I don't know what that is.
Also, I don't know where and how the actual files behind it (VR1) are stored. Any clues as to where they are likely stored on the server?
The viewer uses a java applet. There are plenty better options that don't use java, which in light of recent announcements with regards to security, and it's decreasing scope of use in web pages, is likely to be disabled on many computers.