EJB is the distributed component paradigm in the Java-J2EE world. EJB proved not to be a push button solution for programming problems. Still, a few of the promises (of course, reality too)—distributed transaction propagation, component-based deployment model, and interface-based design, proved to be really useful. Today, we have been talking about lightweight containers and aspect-based programming, and whether EJB still holds the crown is something which has to be answered on a case by case basis. Being neither a proponent nor an opponent of EJB, one thing I have to admit is that the industry has a lot invested in this technology. Scraping all these investments and implementing alternate solutions is surely not a topic for our discussion, at least in this text book. For our SOI-based discussion, perhaps, it is more interesting to look at how to reuse those existing investments. Hence, we can continue building newer system based on higher levels...