Appfuse comes with a lot of libs. Here are what some of them less commonly known ones do:
ClickStream
Opensymphony utility to track the current users on your site, and where they've been in detail. This allows you to track 'click streams' or 'traffic paths' across your site.
dumbster.jar
The Dumbster is a very simple fake SMTP server designed for unit and system testing applications that send email messages. For more information, see:
http://quintanasoft.com/dumbster/