cough Worlds Chat cough Seriously, we had that exact idea implemented around 1997 -- and it even supported multiple authentications (anonymous worlds, versus w

cough Worlds Chat cough Seriously, we had that exact idea implemented around 1997 -- and it even supported multiple authentications (anonymous worlds, versus worlds with user accounts) all transparently. And it could even do VRML, crowd control, dynamic downloads (so you could link to new worlds), and a built-in world builder. It seemed that we had thought of everything... And then management took over.