Gary Holian is an author of several products and articles for Dungeons & Dragons, especially for the World of Greyhawk campaign setting. He also runs the Greytalk electronic mailing list and the Canonfire! website, both of which serve as outlets for fans of the Greyhawk setting.
Holian has authored or co-authored several works, including the Living Greyhawk Gazetteer, the Dungeons & Dragons Gazetteer, and articles for Dragon, Dungeon, the Living Greyhawk Journal, and Polyhedron.