Enterprise JavaBeans is a cross-platform component architecture
for the development and deployment of multi-tier, distributed,
scalable, object-oriented Java applications. Enterprise JavaBeans
makes it EASY to write business applications as components by
providing a set of automatic services to support scalable
transactional application server components. Enterprise JavaBeans
can be deployed on top of existing transaction processing systems
including traditional transaction processing monitors, web servers,
database servers, application servers, etc (from the FAQ).