Garry's Mod

Garry's Mod screenshots

Garry's Mod is a Sandbox Game based around the idea of building
Main Interface
Garry's Mod 14.0 : Main Interface

Alternative downloads

Dream Cars
It's a time management game in which you manage a racing car shop.
The Sandbox of God Remastered
Game where you play as God.
Garry's Mod - Prop Hunt
Garry's Mod - Prop Hunt plays much like a hide and seek game.