We recreate the calculation refactoring example from the open source conference and invite viewers to try it themselves.
YOUTUBE L3fcYFQv6S4 Ward repeats the OSCON demonstration using only resources available on this site.
Notice that pages I change turn yellow. That shows that they are saved in my browser, not the site.
Notice that I sometimes hold the shift key down while clicking links. That adds the linked page without removing others.
Watch more videos 
that chronicle federated wiki's creation.
Try this yourself on the OSCON 2012 Demo Pages.