Tried playing with a friend of mine recently. There were no servers to be seen and when we tried hosting a game neither of us were able to see those.

When it comes to the first part, I believe any official servers have been pulled down and now the only way to play together is for one person to host a session. As for the sessions not being seen, it's anyone's guess, but I assume some port forwarding settings may be necessary here.

It would be great if DuskWorld offered server binaries allowing anyone to host a persistent, dedicated server, but sadly that is not the case :(