If you’re one of many people who still enjoys Dungeons & Dragons third edition, you maybe running short of game material now that many publishers have switched to producing fourth edition books. Thankfully, there are there online sources for third edition game material.
The first is The Grand OGL Wiki, a site collecting third edition open game content from contributing publishers. The wiki currently contains material from Paizo’s Rise of the Runelords adventure path and Mongoose’s massive Quintessential series, amongst others. All material is available for free, so if you missed out on these the first time around you can enjoy a supply of fresh 3E content.
The second is Dungeon a Day, a new project by Dungeons & Dragons third edition co-creator Monte Cook. Dungeon a Day is a service offering daily game content that builds to a complete D&D campaign. There’s a subscription fee, but if you’re looking for official-quality material it’s hard to go wrong with the guy who made the game.
Finally, it’s nothing new but the The Hypertext D20 SRD includes an invaluable set official open content. In addition to the core rules, d20srd.org has added the Epic level rules, Psionics rules from the Expanded Psionics Handbook, the Divine rank rules from Deities & Demigods, and the variant rules from Unearthed Arcana including bloodlines, racial paragon classes, flaws, traits, armour as damage reduction, comabt facing, action points and spell points. The site also includes tools for rolling dice, calculating encounters and searching for monsters and spells.