Tor'Dath is publicly available D&D campaign setting currently licensed under Creative Commons Internation 4.0 (until a lawyer comes along and tells me I have to change it). The goal is a fully functional D&D Campaign setting for D&D 5th Edition that is 100% free for reuse.
It is written by Joshua Lee for his D&D Campaigns you can follow the bulk of the writing progress here on Kanka. It's still under active development and feel free to help contribute. ...