Evil Hat Productions published the Fate Freeport Companion under the 1.0 OGL with Green Ronin Publishing as the primary author, with no credit to Wizards of the Coast other than the text of the license.
15. COPYRIGHT NOTICE
Open Game License v1.0 Copyright 2000, Wizards of the Coast, Inc.
Fate Core System and Fate Accelerated Edition ©️ 2013 by Evil Hat Productions, LLC. Developed, authored, and edited by Leonard Balsera, Brian Engard, Jeremy Keller, Ryan Macklin, Mike Olson, Clark Valentine, Amanda Valentine, Fred Hicks, and Rob Donoghue
FATE Freeport Companion, Copyright 2013, Green Ronin Publishing, LLC; Authors Brian Engard, Robert J. Schwalb, and Clark Valentine
In accordance with the Open Game License section 8 "Identification" the following designate Open Game Content and Product Identity:
OPEN GAME CONTENT
The entirety of Chapters One through Three, all statistics excluding proper names in Chapters Four and Five, and statistics present in Fury in Freeport.
PRODUCT IDENTITY
Freeport: The City of Adventure and all proper names.
-- The Fate Freeport Companion p.192, "License"
To very slightly elaborate, the book comprises five chapters and the "Fury in Freeport" sample adventure.
There is no d20-facing material in the book; the "Freeport Companion" series were intended as rules affixes for the systemless setting book The Pirate's Guide to Freeport, which Green Ronin Publishing publishes under its own imprint.
The Fate rules, per p.2 of the frontispiece, are "licensed for our use under the Creative Commons Attribution 3.0 Unported license (http://creativecommons.org/licenses/by/3.0/)".