The program
      lives entirely at http://example.com/mail, but includes an inbox, a contacts area
      and a calendar. Links or buttons are provided that cause the inbox, contacts, or calendar
      to display, but do not change the URI of the page as a whole. Example 3 A customizable portal site, where users can choose content to display from a set of
      different content modules. Example 4 When you enter "http://shopping.example.com/" in your browser, you enter a movie-like
      interactive shopping environment where you visually move around in a store dragging
      products off of the shelves around you and into a visual shopping cart in front of
      you. Clicking on a product causes it to be demonstrated with a specification sheet
      floating alongside.