On the Tomcat FAQ it says: "Tomcat is not an EJB server. Tomcat is not a full J2EE server."

But if I:

• use Spring to supply an application context
• annotate my entities with JPA annotations (and use Hibernate as a JPA provider)
• configure C3P0 as a connection pooling data source
• annotate my service methods with @Transactional (and use Atomikos as JTA provider)
• Use JAXB for marshalling and unmarshalling
• and possibly add my own JNDI capability

then don't I effectively have a JEE application server? And then aren't my beans EJBs? Or is there some other defining characteristic?

What is it that a JEE compliant app server gives you that you can't easily/readily get from Tomcat with some 3rd party subsystems?