It seems there are only a handful of games supporting OSVR 

https://itch.io/games/osvr 

Going by Steam it would seem VR devs are mostly using either unreal or unity, are there any open source game engines which have implemented Valve's openVR API?  

https://github.com/ValveSoftware/openvr/wiki/API-Documentation 

It seems like a great opportunity for open source games to get some limelight.  Early VR games don't always have the most amazing graphics, and most games are in early development.  Simply porting an existing open source game might be enough to get significant take up, for instance Minetest could leapfrog Minecraft into VR and take off big time.

Anyone know of any open source VR game projects around?