You can find the full source code for this website in the Seam package in the directory /examples/wiki. It is licensed under the LGPL.
Seam can be used in a portal implementing the Portlet 1.0 (JSR-168) or Portlet 2.0 (JSR-286) specifications (Only tested with JBoss Portal at this time). To do so, you need to use Seam along with the JBoss Portlet Bridge (http://labs.jboss.com/portletbridge) which also supports RichFaces. The bridge comes with a demo of the Seam booking example as a portlet and can be seen here: http://portal.demo.jboss.com/portal/default/SeamBooking