This week marks a milestone for Bohemia Interactive. The studio is celebrating its 15th anniversary and it plans to do so in style. The entire Arma library, including DayZ, will be discounted on Steam for the next few days and Arma 3 players will get a chance to play the game for free this weekend. Bohemia is also offering something special for Arma fans by offering their debut game, Arma: Cold War Assault for free until Monday.