Actually, Series Archer was originally planned to be a standalone OGL-based product, not bearing the trademarked "d20 system" logo.
But somehow, they were convinced to take advantage of the d20 market. So it became a d20-based product, complete with the logo and full compliance of the d20STL.
Of course, they renamed it Shadowforce Archer due to a confusion with another trademark, and not willing to challenge it.
But all in all, Spycraft Espionage Handbook began showing up on the store shelves early Spring 2002. So yeah, it does have a bit of a headstart. By the time d20 Modern Core Rulebook debuted to the public, AEG managed to roll out Spycraft Game Control Screen, Modern Arms Guide, Soldier/Wheelman Guide, Shadowforce Archer Campaign Setting Book, The Archer Foundation Chamber Book, and Hands of Glory.
Since d20 Modern up until now, they released Gentlemen's Agreement Series Campaign and Pan-Asian Collective.
Correct me if I'm wrong.