The Source Engine is a game engine developed by Valve Corporation. It powers many popular video games, including the iconic Half-Life 2 and the multiplayer shooter Counter-Strike: Source. The engine is known for its advanced graphics, physics simulation, and support for modding, allowing players to create custom content. First released in 2004, the Source Engine has undergone several updates, enhancing its capabilities over time. It supports various platforms and features tools for developers, such as the Hammer Editor for level design. The engine's flexibility has made it a popular choice for both commercial and independent game developers.