Philip Rosedale - the creator of Second Life has an ambitious plan to create a decentralized virtual reality consisting of voxels. The only way he's going to make profit are services like DNS.
His virtual world is going to have a cryptocurrency rewarded for contributing your computing for simulation of the world, the computation could be even done by a smartphone.
It is going to have implemented support of Oculus Rift, Leap Motion, Kinect etc. and it is going to be expandable. The world and the interface can be programmed through JavaScript.
The project has a significant funding and is open-source from the beginning. You can take part in a development too and even earn some money - details can be found on their
website.
You can see the current progress on
Silicon Valley Virtual Meetup #9 video, it is impressive how much they have already done.