DayZ is an open world survival video game currently in development by Bohemia Interactive. It is the stand-alone successor version of the award-winning mod of the same name. The game was released for Microsoft Windows via early access on Steam on December 16, 2013, and is currently in early alpha testing.
http://dayz.com
Miscreated is a multiplayer, post-apocalyptic, survival-based sandbox game created using CryEngine. It's now available for Early Access on Steam and is in the Alpha stage.
http://miscreatedgame.com/