1.2. Why JBoss?
JBoss fits the "I just want to make it work" gestalt to a T. Depending on the speed of your Internet connection, you can have it downloaded, unzipped, and running in less than five minutes. Turning services on and off is as simple as adding or removing files from a directory. The fact that it's free means that you don't get bogged down with per-seat or per-CPU licensing costs. JBoss is both a great learning tool and a production-quality deployment environment.
But any tool as powerful as JBoss also has pitfalls and complexities. The biggest disservice we could do is show you how to write applications that are tied to a specific application server, JBoss or otherwise. The "Write Once, Run Anywhere" promise of J2EE development may not happen automatically, but you can take steps to minimize the impact of moving from one application server to the next. In addition to your code being more portable, being a non-partisan J2EE developer means that you and your skills are more portable as you move from one job to the next.