Arma 2 Free
Some of the key features of Arma 2: Free include:
.Free military simulation - An authentic battlefield simulation, including bullet ballistics, material penetration and much more.
.Free armory - A comprehensive range of 300+ weapons, units and fully-usable armed or unarmed vehicles across air, land and water classes.
.Free unique multiplayer - Multiplayer with large-scale maps for 50+ live players and hundreds of AI units. Supports a wide variety of MP modes from co-op and PvP modes, to total mayhem!
.Free dedicated servers - Both Linux and Windows OS dedicated server support for users to host freely wherever and however they like even to play together on the same retail game-servers.
.Free creativity - Quick mission templates, a powerful, built-in, easy to use SP/MP mission editor, and advanced scripting.