Steam turns 20 today, and Valve is celebrating by hosting a sale on all its titles.
Alongside the sale, Valve also provided a list of games that were the top releases on Steam each year, and many of those games are joining the 20th Anniversary celebration with discounts of their own.
Steam was announced in 2002 at the Game Developers Conference (GDC) as an easier way to deliver Valve game updates, with the ultimate goal of providing game developers an opportunity to build audiences directly.
Counter-Strike: Condition Zero was the first game released on Steam in 2004, and Half-Life 2 followed later that year along with the first third-party game for the service: Codename: Gordon - a 2D Flash sidescroller shooter developed by NuclearVision as a promotional game for Half-Life 2.
In 2008, Valve introduced Steamworks along with Steam Cloud, and two years later, in 2010, MacOS support was added to Stream, and Steam Play was launched to support Linux users. Steam Wallet and the TF2 in-game store also came out in 2010.
2011 saw players able to add screenshots to Steam, and Steam Guard was introduced, as was the centralized place for player-created content: Steam Workshop.
Steam Greenlight went live in 2012 to streamline how titles came to the service, Steam Community and Steam Community Market went into beta, and Big Picture Mode launched, allowing you to pair your PC with a TV and controller.
Steam added features that include trading cards, family sharing, and player reviews in 2013, plus started offering the option for developers to launch games in Early Access.
The Discovery Update arrived in 2014, which was also the year Steam got the in-home streaming and broadcasting feature, and SteamVR was released for the Oculus Rift.
Steam added a hardware section supporting Steam Controller, Steam Link, and Steam Machine in 2015 - the same year Steam Refunds became a thing. The first annual Steam Awards happened in 2016, and Valve teamed up with HTC to release the HTC Vive headset that same year.
Steam Greenlight was phased out with Steam Direct in 2017; in 2018, Steam Chat launched; Remote Play Together went live in 2019, as did the mobile app for Steam Chat, an update for Steam Library, the inaugural Steam Next Fest, and Steam Labs; finally, in 2022, Valve launched Steam Deck.
There's more to the Steam timeline through here, along with other nuggets of information about each year. You will also find a nice batch of games on sale broken down by year of availability when clicking that link.
Happy Birthday, Steam!