(last updated 2012-09-23) Resource Identifier (RI) Scheme name: steam Status: provisional Scheme syntax: steam: or steam:/// Scheme semantics: Interact with Steam: install apps, purchase games, run games, etc. Encoding considerations: Unknown, use with care. Applications/protocols that use this scheme name: See official documentation from Valve Developer Community website Interoperability considerations: Unknown, use with care. May be unsuitable for open use on the public internet. Security considerations: Unknown, use with care. Contact: Registering party: Dave Thaler Scheme creator: Valve Software Author/Change controller: Either the registering party or someone who is verified to represent the scheme creator. See previous answer. References: http://developer.valvesoftware.com/wiki/Steam_browser_protocol (file created 2012-09-23)