This should be good news for lots of would-be virtual world developers. From the Multiverse developer forum (Link):
The Multiverse Open Beta platform release is now available. Register with the Multiverse Developer Program, and you will be able to access the downloads here:
I’ve been stopping in to the Multiverse forums on occasion lately hoping to catch that announcement, so for those who were also wondering when it would be made available, have at it. And if you’ve not registered, head there first – Registration Link.