Though initially developed for use on Microsoft Windows operating systems, versions for macOS and Linux were later released. The software provides a freely available application programming interface (API) called Steamworks, which developers can use to integrate many of Steam's functions into their products, including in-game achievements, microtransactions, and support for user-created content through Steam Workshop. It also provides the user with installation and automatic updating of games, and community features such as friends lists and groups, cloud storage, and in-game voice and chat functionality. Steam offers digital rights management (DRM), server hosting, video streaming, and social networking services. Steam has also expanded into an online web-based and mobile digital storefront.
It was launched as a standalone software client in September 2003 as a way for Valve to provide automatic updates for their games and, expanded to include games from third-party publishers. Steam is a video game digital distribution service by Valve.
