Lords of Doom is a software game still in development.
It's a turn-based strategy game, that can be played alone (against AI) or against other through a network (local or internet).
Netrek is a 16-player two-dimensional graphical real-time battle simulation with a Star Trek theme. A game is divided into two teams of 8 players (or fewer), who dogfight each other and attempt to conquer each other's planets.