Does anyone know how this navigation is executed?

Hello Everyone,

I was surfing the web and stumbled upon this site. While watching some of the flash presentations I noticed that the videos had pretty complex navigation. Can someone tell me how it is put together or what kind of tutorials would I need to look at to comprehend how these navigations are done.

The video is located on this site

http://todayspictures.slate.com/themaze/

The video is called
Point and Shoot by Philip Jones Griffiths.