Diorama, is a voxel based game created in C++ and Lua, with the goal of being a highly moddable and customisable experience. The entire development is streamed live by the developer "RobTheSwan" at Rob's Twitch Channel. The game is planned to be officially released in some form around late 2016 or early 2017. Current test versions can be downloaded for free, however as it is in its early days, functionality is limited in comparison to what is currently planned.
Watch the game get developed live here.