Dependency Injection
From APIDesign
A special form of component injection following the classical Hollywood principle: the framework calls, and beans just react to such calls. See wikipedia::dependency injection.
Translation Basics
During our JavaOne2010 talk about Modularity patterns we compared dependency injection and injectable singletons. As the comparison was well accepted and as I think it revealed some things that were just implicitly present in our minds, here is an explicit enumeration. Here is the beginner's guide to modularity of dependency injection (namely Spring) fans.