Lightweight alternatives to heavyweight technologies

• JMS: ActiveMQ

• RDBMS: HSQLDB , Apache Derby, Oracle TimesTen In-Memory Database ?

• In-mem Mongo: Fongo

• Servlet container: Jetty

• LDAP: ApacheDS

• JTA: Atomikos (recommended), JOTM

• EJB3: Spring Pitchfork

• JAX-WS: XFire