Into Cerberon D3 0.1 Linux build
Into Cerberon is focused on the gameplay of the descent games with the doom3 engine. Its multiplayer only in the moment but they discuss about a singleplayer campaign when the time is come.
This version is more like a techdemo but you can see where the game is going into and you can see that the doom3 engine is not only for FPS style games.
Full Story with links.