You must use either Netscape Navigator version 3.0 or above or Internet Explorer version 3.0 or above. Some of the pages include Java applets.
Some pages require both.
You can consult a list of pages requiring these plug-ins. The pages on the site are organized into a tree . That is, each page may have zero or more child pages , but only one parent page. From a given page, you can move to its parent or to any of its children. The children of the page are also listed at the top and sides of the current page.