Free Online Space Battle Game

Netrek is a free online game where you battle against people around the world. Download and play for free. Up to 16 people per game battle against each other over the internet on a virtual battlefield. The ultimate goal is to wipe out the enemy race by taking their planets. Since you are always teaming up with and playing against different people, the game is extremely intense. Each player can fly different types of ships that have different weapons and capabilities. There are multiple servers ready for you to play on and they are online 24x7. Each server can hold 16 people in a game and multiple observers.
http://www.playnetrek.org