"JBoss Tools is a set of plugins for Eclipse that complements, enhances and goes beyond the support that exists for JBoss and related technologies in the default Eclipse distribution.
"Red Hat JBoss Developer Studio is a fully bundled Eclipse distribution which not only includes the majority of JBoss Tools but also all its needed dependencies and 3rd party plugins allowing for an easy one-click and no-fuss installation.
"If you are into doing your own bleeding edge Eclipse plugin assembly, JBoss Tools is for you; if you are more into having something that "Just Works" then JBoss Developer Studio is the way to go. "
Posted by Fred Bricon of Red Hat. Read the whole article - JBoss Tools: JBoss Tools 4.1 and Red Hat JBoss ... | Community.