Vox-L began as part of LearnToMod -- software that Stephen and Lindsey built to teach Minecraft modding to kids. But they are currently developing it into a variety of standalone experiences.
The goal is to make a voxel-based experience with all the things you expect from a modern game: great lighting, great physics, great textures, and great art assets. Additionally, the vision is to make it highly moddable.
Here's a tech demo where Lindsey defined a custom block, built a container out of it, filled it with colored balls, and then started messing with gravity. It's nuts.
Here's a tech demo where Stephen created some custom weapons (light sabers!) -- one for himself and one for an NPC. Then he totally owned the NPC. Poor thing.
It currently works on Mac, Linux, Windows, and in web browsers. We're planning a Virtual Reality release. We haven't decided about consoles yet.
We get asked a lot about what features will be in Vox-L when we officially release it. Usually people want to know if their favorite feature from Minecraft will be in the game. We don't really know yet. Our vision is to create the ultimate creative sandbox -- and to make it moddable. Build your own worlds. Add your own blocks. Add your own creatures. Share your mods with friends. Get mods from the community. Hopefully, that means Vox-L will have all the features you've dreamed of and more.