Steam is a digital software distribution platform, developed and published by Valve Corporation. Steam is widely known for its video game distribution; however, since May of 2008, Valve's software development kit (SDK) has made it possible for any software to be uploaded to the Steam store. The software also provides friend lists, voice and text chat, automatic game updates and cloud saving.

Steamworks, Valve's API, allows for game developers to integrate Steam functions into their own games. The API is free and allows features like achievements, automated online matchmaking, microtransactions and support for user-created content from the Steam Workshop.

Steam is the largest PC software distribution platform, holding 75% of the market space in 2013. In 2017, Steam's total revenue from all software purchases combined totaled $4.3 billion, which was 18% of global PC software sales at the time. By 2019, over a billion users had registered for the software, with 90 million being active monthly. Following this success, Valve has released the Steam VR and Steam Controllers hardware platform.


Before the release of Steam, Valve had had troubles with updating online-based games, such as Counter-Strike. Releasing patches for this game would result in the servers for the game being down for several days at a time. Following this, Valve had decided to release a software which had stronger anti-cheat measures. A poll held by Valve in 2002 showed that around 75% of their users had a high-speed internet connection, realizing that they could increase sales and their user-base by releasing their games on an online, retail-based site. Valve had approached several companies to help with this, but were declined.

Steam was eventually released on September 12, 2003, following the announcement at GDC a year earlier. This followed a beta test prior, where up to 300,000 users participated. Valve did not anticipate the overwhelming amount of users that would sign up and use the software, therefore the servers were insufficient and Steam was down for days at a time while Valve was attempting to upgrade the servers to cope with the amount of users.

Half-Life 2 was the first game that required Steam to activate and play, including retail copies, sparking outrage and concern about the future of digital software management platforms. Users faced a multitude of issues while attempting to run the game.

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