CDI came after JSR330 I think. I was on the JSR330 experts group. I could be wrong there.
Back history of dependency injection - it was an antidote to classic GoF service-locator being used everywhere in Javaland. When we co-created PicoContainer we were careful to avoid Singleton as a term or idiom for good within the classbase and documentation. GoF singleton being a sibling of service locator. Spring used the term in XML, then later as an annotation (after Guice used Singleton as an annotation when Java5 kicked off). Then JSR330 gets to include it in the set of annotations. Anyway, I always told readers "single managed instance" was the thing you were trying to do. That could be one per JVM for a flat classloader design. Or in a hierarchy of classloaders (Tomcat, Intellij, a stupid Jesktop <http://jesktop.sourceforge.net/> thing I worked on) it would be one per meaningful separate part of a tree of classloaders in a JVM. These days, twice a year I get to give an opinion of a technology in a language that purports to be DI, but is actually Container.getInstance().getComponent(<some key>) by various obfuscations (service locator *not* DI at all). - Paul
