RolePlayingMaster
- A software utility suite for D20/D&D, incorporating character/NPC/monster generation, adventure building, and in-game combat/BattleMap manager.
- http://www.enworld.org/RolePlayingMaster/

Fantasy gaming SRD
- SRD for d20 roleplaying games in a fantasy setting.
- http://srd2.astrally.com/

RPGAttitude: D20 RPG Site
- A website that contains new generator programs for the D20 system such as the NPC and Treasure Generator.
- http://www.rpgattitude.com

Modernized! - D20 Modern Ezine
- A free ezine, published to the web, that provides new material, suggestions, and other useful bits for a D20 modern campaign.
- http://www.intrepidheroes.com/modernized.htm

The Hypertext d20 SRD
- Contains the version 3.5 d20 system reference document and is indexed, hyperlinked, and searchable.
- http://www.d20srd.org

Palaestra: A Land of Magic and Intrigue
- Maps, fictional stories, artwork, house rules, campaigns, and general game information
- http://webpages.charter.net/wpeacock/palaestra/

Ruby Covenant Roleplaying
- Australian based web site that offers D&D & d20 roleplaying information and products to RPG fans.
- http://www.rubycovenant.com.au

SVGames - Global Game Source
- Offering d20 games and accessories worldwide. Cheap shipping and thousands of items. Managed by an award-winning team.
- http://www.svgames.com

d20 Modern Roleplaying Game
- The official site for The Wizards of The Coast d20 Modern RPG. Features free articles, downloads and artwork for the game.
- http://www.wizards.com/default.asp?x=d20modern

Starcon Continuum Homepage
- New rules for a futuristic D20 campaign. Has information on starships, new skills, weapons, along with bios of characters in the world.
- http://starcon.ionichost.com

DireKobold.com -- A D20 Adventure E-Zine
- An internet D20 adventure magazine dedicated to the three principles of quality, quantity and flexibility.
- http://direkobold.com

PCGen
- A character generator and maintenance program aimed at supporting any and all d20 roleplaying games.
- http://pcgen.sourceforge.net/

Weird War II - The Complimentary Website
- Has variant rules, new equipment and vehicles and information for the PEGInc game Weird War II: Blood on the Rhine (and expansions).
- http://www.mchome.net/dirk/weirdwars/

d20 Magazine Rack
- A site that has free downloadable electronic magazines such as d20Zine and TempesT's Lore, product reviews, gamer resources, and gaming contests.
- http://www.d20zines.com

Salon Technology: Dungeons & Dragons to go open-source
- An interview with a gaming executive about an open gaming license for role-playing games.
- http://www.salon.com/tech/log/2000/03/10/dungeons/index.html

RPGd20
- News and a list of all the companies making d20 products.
- http://www.rpgd20.com/

Open Gaming Foundation
- Contains Open Gaming Licenses and a clearinghouse for information about the system.
- http://www.opengamingfoundation.org/

creaturedb - the RPG monster database
- Open, free, online database for rpg monsters, creatures and npcs. Accepts (and encourages) submissions for home brewed monsters / beasties. Authors/copyright holders receive full credit/ownership/copyright for their work.
- http://creaturedb.thathobbyplace.com/

Slashdot: Where Daemons and Dragons Collide
- Feature story of the Open Gaming Project with reader feedback.
- http://slashdot.org/features/00/03/22/0950237.shtml