In 2004, original Counter-Strike developers Minh Le and Jess Cliffe, along with members of Valve and the Day of Defeat team, brought Counter-Strike into the Source engine as an obvious choice for the multiplayer component of Half-Life 2. Following a period when the game was available to select "beta" testers, the game went gold on October 7, 2004. Counter-Strike: Source(CS:S) was released to ATI Radeon Voucher holders, in Half-Life 2 bundles available on Steam, and with the boxed retail version of the game. Changes include the improvements inherent to the Source engine (such as better graphics and physics) as well as updated models, animations, maps, sounds, and some small gameplay changes. For what Counter-Strike and its popularity is concerned the new Source engine heralds a new beginning for the most popular first-person shooter in history, a game which has been played throughout the world for more than six years.