Garry's Mod is a sandbox game developed by Facepunch Studios and published by Valve. The game was created by Garry Newman as a mod for Valve's Source game engine and released in December 2004, before being expanded into a standalone release and published by Valve in November 2006. Ports of the original Microsoft Windows version for Mac OS X a…New content will be added above the current area of focus upon selectionGarry's Mod is a sandbox game developed by Facepunch Studios and published by Valve. The game was created by Garry Newman as a mod for Valve's Source game engine and released in December 2004, before being expanded into a standalone release and published by Valve in November 2006. Ports of the original Microsoft Windows version for Mac OS X and Linux followed in September 2010 and June 2013, respectively. The base game mode of Garry's Mod has no set objectives and provides the player with a world to freely manipulate. Other game modes, notably Trouble in Terrorist Town, are created by other developers as mods and are installed separately, by means such as the Steam Workshop. As of December 2019, Garry's Mod has sold 15 million copies.