Don't underestimate the power of Phil Reed....
* One book detailing new races, classes/prestige classes, feats, equipment, magic, and optional Combat or Magic rules for d20 System Fantasy.
* One book detailing new allegiances, starting occupations, feats, equipment, advanced classes, creatures, FX abilities, and campaign models for d20 Modern.
* One book detailing new aliens, starting occupations, campaigns, gear, starships, vehicles, mecha, robots, cybernetics, mutations, and optional "advanced science" rules foe d20 Future.