UltraCorps by Microsoft. In UltraCorps you are fighting to gain galactic control against literally thousands of opponents. You can choose from 14 different alien races which will determine your starting weapons, home planet resources, and perhaps with whom you will create alliances. Regardless of your choice, you can quickly, through purchase or conquest, develop new weapons and technologies you will need to dominate your friends and enemies.
Social interaction is crucial in the game.
I found that it was a necessity to cultivate good relations with my neighbors, create alliances and treaties, join forces against invading opponents, and conduct deception operations. UltraCorps does not require any software to play, except for either Internet Explorer or Netscape Communicator 4.0 browser to connect to the Microsoft Internet Gaming Zone. The game has an intuitive browser feel to it that I found easy to use. There is a straightforward online tutorial, as well as a help section, which can take care of most of your questions. I also found good, but varied advice on strategy on the main site and in the newsgroups.