Divinity: Original Sin is the latest game by Larian Studios and was successfully Kickstarted last year. Afterwards it landed on Steam Early Access and is about to graduate to a full release. Players get more than just the game with purchase, though.
Also included is the Divinity Engine Toolkit. With this Toolkit players can make their own stories, missions, multiplayer modes and maps, and basically edit anything else as they see fit. Overwhelmed by the options? Well, Larian Studios created a lovely little demo mod to get ideas flowing with Cow Simulator 2014. It showcases just how much can be tweaked by creators with a vision. Funnily enough, Cow Simulator 2014 is also a fully playable demo with co-op for up to 4 players.
Current Early Access owners can already take the Divinity Engine Toolkit for a spin. It will also be available with the release of Divinity: Original Sin on June 30.