Hello, I'm working on 2x action MMO engine's:
Pricing for mod+resell commercial license:
https://tinspin.gumroad.com (for both dedicated server and source access resell)
Read more about the 3D backend here: https://multiplayeronlinestandard.com
The 3D engine will probably be in parts closed-source.
The 3D engine's world will be voxel based so I'm delaying the release.