Usually when you install a Web Application you assign its own domain for it, but there are a handful times when you want to install two or even more applications under the same domain. For example, let’s say you have a Wordpress blog, and you want to use ZenPhoto for your photo album, and just to complicate it a little more you want to have a forum managed by Discourse. Sure you can just use Wordpress plugins to make Wordpress manage all of these, or use Drupal or any other thing, but for this example let’s suppose you want to do it this way.