Bruce R. Cordell is a game designer chiefly responsible, alongside Monte Cook, for the resuscitation of Dungeons & Dragons in its second edition and, thereby, for the foundations of the third. The Far Realm is his baby.
Cordell basically picked up where Carl Lynwood Sargent left off.
Cordell was a biologist by training, like Sargent was a psychologist, before entering this hobby as a writer. Where Sargent featured horror and madness (and the Underdark), Cordell's best work tended to the Weird Science that leads to such ends. His second-edition credits include Gates of Firestorm Peak, the extension of Tomb of Horrors, and the Illithiad. And holy shit he co-wrote Die, Vecna, Die!. With John Rateliff: Reverse Dungeon.