> And it always had a single official and complete reference implementation in the form of the Sun JVM and later the OpenJDK. kbensons description makes it look as if Perl 6 had/has neither.

It had and has a spec. It's been evolving over time though. It was ambitious enough that no one implementation ever fully implemented it until recently, if ever (I stopped following the project actively a few years back. I'm not sure if any current implementation is fully compliant). That's not a surprise, it's an amazingly complex set of features that are describes, and there's many specs that are never fully implemented, and it's not uncommon to have an aggressive specification run up against reality when people try to implement it. For example, I've heard that the IMAP spec has never been fully implemented, or at least the later ones versions of it.

So, they have a spec, and have had one for a very long time. They have implementations that do the vast majority of the stuff you'll want from that spec, and they've been in that state for a few years.