Does anyone know any game engines (multiplayer) that support terrain modification (I've seen it called many things). To be specific, I mean a multiplayer game engine that allows you to dig holes / tunnels in the ground or create hills. I'm not looking for something like Minecraft or Wurm Online... more like StarForge or RealmExplorer.
I've done a lot of looking around, but I've not really found anything. To be a little more clear, I dont mean something like APEX Destruction.