Steam News reflects back on the two years since Valve hired the developers of Alien Swarm, saying they have not forgotten the game, and that in between other projects, the team spent a lot of time bringing the game to the Source engine. Their plan is to release the updated version on Monday for free, along with an SDK, saying: "In addition to the game, Valve will also release the complete code base for Alien Swarm. This includes updates to the Source engine SDK and full Steamworks integration. If you’ve ever thought about developing a mod on the Source engine with Steamworks, this release provides more insight and examples for using Steamworks in game production."