Platinum Arts Sandbox - Free 3D Game Maker Forum

So I've had the idea for a while of creating a sandbox game where you gather resources and build things in a world. I guess this is similar to Wurm Online or maybe even Minecraft. I'd like to try my hand at such a project. However, is Sandbox the right fit? There is some functionality that the player must be able to do. They will have to be able to impact the world by terraforming and creating objects. I was thinking that there would not be a server/client model in the traditional MMO sense. Players could host their own servers, and create a "stargate" for lack of a better term that would allow them to go to another servers. Also, players could build, visit, etc in each others worlds.

So anyway, since you guys know Sandbox a bit better than I do. Is it feasible or should I continue looking for an engine that might be a fit?

I don't believe terra-forming would be possible in Sandbox without some sort of modification. Creating things wouldn't be too hard depending on what you want, but once again, some things would require modification.

I'll let others weigh in on this one though...

Well Sandbox is based on the Sauerbraten Engine, which features ingame world editing.
Someone already made a Minecraft-like modification of Sauerbraten: http://www.youtube.com/watch?v=dKng8p4YNlM
So it's quite possible, but with source editing, that means you need to know how to script in C++.