Mobile apps to access online Steam features were first released for iOS and Android in 2012. Initially developed for Microsoft Windows operating systems, Steam was released for macOS in 2010 and Linux in 2012. Many game publishers began distributing their titles on Steam that year. Valve released a freely available application programming interface (API) called Steamworks in 2008, which developers can use to integrate Steam's functions into their products, including in-game achievements, microtransactions, and user-created content support. Steam client's functions include game update automation, cloud storage for game progress, and community features such as direct messaging, in-game overlay functions and a virtual collectable marketplace. Steam offers various features, like digital rights management (DRM), game server matchmaking with Valve Anti-Cheat measures, social networking, and game streaming services. It was launched as a software client in September 2003 to provide game updates automatically for Valve's games, and expanded to distributing third-party titles in late 2005. Steam is a video game digital distribution service and storefront from Valve.
