Too many people still believe that a JCP
Reference Implementation is always just a "Proof of Concept".
Although some are, there are many that are fully production-quality, and,
in particular, the Reference Implementation for Java EE has been production quality at least since
SJS AS 8.x,
so please help us spread the word.
I wrote a blog at Java.Net expanding on the relationship between
Reference Implementations and Production Implementations.
You may also want to check out our earlier
20 Things You Should Know about Project GlassFish.