Mobile apps were also released for iOS, Android, and Windows Phone in the 2010s. 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.
