Being able to play without having friend logging on?

[Dilligan]

Is it possible to setup a world where my friends can join and play at anytime without having the original owner of the world being forced to log on so others can play?

[Louie]

I’m afraid that you cannot do that as of right now. There might be a mod for that though.

[Buzzard]

Currently, the host *IS* the server. Without the host/owner, there is nothing to play on.
As mentioned, there's a server mod in the works that will act as a host, allowing ALL allowed players to come and go at will, so long as the server is running.