From the introduction:
In June of 2015, Purple Duck Games published Drow of Porphyra: The Karza, Children of the Loomqueen without the Pathfinder Compatibility License; this product explored some mature themes that were appropriate for Porphyra but not for the compatibility license.
As 2015 progressed we released more supplements using open game content from Pathfinder Roleplaying Game but abandoned our claims of official compatibility as we actively worked to change some minor aspects of the game both in our products and at my gaming table. Now with the recent announcement of what is generally being referred to as "Pathfinder 2.0", we have decided to formalize our work as the Porphyra Roleplaying Game.
The evolving core rules of Porphyra Roleplaying Game are iteratively published for public review, play, and comment, under the document title "A Work-In-Progress".