AppFuse

AppFuse is a kick-ass combination of test-first, open-source packages for writing web applications all rolled up for you. It includes O-R persistence (hibernation), a framework (struts), automated configuration generation (xdoclet), soup-to-nuts testing (too many to list :-) and an out-of-the-box login management system. What a superb demonstration of smart integration. If only the commercial world could do as well.