SandBox Wars 3D is the game I have been writing for my whole life. I changed some of the ideas between an iteration and the other, but the concept always remained the same.
I tried implementing SandBox Wards 3D in various languages and engines, I even wrote a few libraries to do stuff for this game, including a mid-level network library, a math library and a C# Linux (Mono) port of Lidgren.
Here are a few random documents I've written in the past about this game, please read first chapter of "Game Concept" to get an idea about this project.
Documents: Game Concept, Socket Protocol, Game Draft.
Here's a link to the official GIT repositories; game server and database driver are private, everything else (including client) is public and open-source.