We now have our own Worlds.com private server:
worlds.worlio.comFAQQ: Is VIP free?
A: Yes. You do not need to participate in events or pay money for VIP.
Q: What features are working?
A: All of them! Except for Voice Chat and WorldsMail, which we are working on.
Q: How do I register?
A: Use the link above, or go to worlds.worlio.com in your browser.
Q: Do I need the Worlio server to use Worlds?
A: No but also yes. There is a work-in-progress, free software reimplementation of the server called Libreworlds which aims to be compatible with the original software and improve upon it. You should support them as well!
You can also browse Worlds.com without any server by launching in Single-user Mode. You will still be able to explore Worlds, even custom-made rooms from the Internet, but you will need a server to chat with other users.