I am reading "Ready Player One". It describes a world connected to a virtual world that is a real evolution of OpenSim. It talks about the inventory, the point on the avatar that can talk, places where you can be damaged, you can have the skin of an elf or a human, the hypergrid, ...
Oh yes, I ran a Pern type MUSH for a while called Silver Skies. I lost a lot
of interest when my wizards started infighting. I left the internal
management to my wife and focused on maintaining the server its self. Lost
even more interest when I was introduced to Second Life and its potential.
Finally, there was Opensim where I pretty much could "have it all." An
environment in which I could play and have full control over the server.