A full version program for Windows, by TRION WORLDS.

Defiance is a free MMORPG with a story-driven single-player campaign and competitive multiplayer PvP battles. It was developed by a small team of people and is the first and only MMO with a story-driven campaign. You play as the last remaining human, fighting against a race of aliens who want to take over the planet. 

Defiance is a huge, open world with a unique and beautiful style. It has an interesting story that brings the world of the Defiance to life. You will meet other players and interact with them.

Defiance has a class system that is a little different from other MMORPGs. You can develop your character as you select new abilities.