"Hey gamers, we bring great news about Firearms: Source's distribution and publicity. We at Firearms: Source like to patch our game frequently, which should normally be a good thing. However, this means servers and clients have to keep making sure they have the latest version of Firearms: Source. How do we solve this? Steamworks!
The next version of Firearms: Source will be released via Steam as Firearms: Source 2.0. We have so much new content and new features being packed into the next version of Firearms: Source, that it will once again feel like a whole new game. With Steam works, your clients will auto-update whenever we release a new build, and Steam will install the game for you. Also, expect some Steamworks features like Achievements and Player Stats. - Source [2]