WotC releases old Dungeons and Dragons catalog as PDFs

jjohn writes: "Wizards of the Coasts, holders of the TSR catalog, has released rulebooks and modules for most editions of Dungeons and Dragons through a partnership with DriveThruRPG.com. The web site, dndclassics.com, may be a little overloaded right now. Most module PDFs are $4.99 USD."