Garry's Mod is a 2006 sandbox game developed by Facepunch Studios and published by Valve. The base game mode of Garry's Mod has no set objectives and provides the player with a world in which to freely manipulate objects. Wikipedia

Initial release date: November 29, 2006

Designer: Garry Newman

Engine: Source

Developers: Facepunch Studios Ltd, Facepunch Studios

Platforms: Microsoft Windows, macOS, Linux, Classic Mac OS

Modes: Single-player video game, Multiplayer video game