DR is a developer release. If some things are broken you get to keep the pieces. It just means that things are in a state of flux with a lot of new functionality for hard core developers to play with and get early exposure.
RC3 is a release candidate - just about ready for release but some additional field testing required.
Try 3.2.1. Jetty or Tomcat are your embedded servlet containers. Your choice as to which one to use. Just unpack it and make sure JAVA_HOME is set for your environment. Don't have any special classes in your classpath before you start JBoss.