iBATIS.com "JPetStore is a completely rewritten Pet Store application based on Sun's original J2EE Pet Store. The primary difference is that JPetStore uses a design competetive and comparable to the Microsoft .Net Pet Shop, but without its shortcomings.
The benefits of the JPetStore implementation are:
Vendor independence: including Database, Application Server and Operating System (tested with PostgreSQL, PointBase, Oracle, Tomcat, Windows, Linux and Solaris).
Very low implementation cost (FREE): all tools and runtime environments used in implementing JPetStore were open source freeware including Linux, Tomcat and PostgreSQL"