D20 System, a Role Playing Game System

• Dragonstar
• Spycraft

• Publishers

• Ancient Worlds: Multicosm  - Contains adventure ideas, campaign seeds; and variable rules, monsters, classes, and feats. Also provides product reviews.
• d20 Magazine Rack  - Provides downloadable magazine containing rules variables, plot guides and player resources relevant to the gaming system.
• The d20 System  - Official site of the gaming system. Shows product lists, RPG facts, and official licenses.
• EN World  - Provides product reviews, interviews with the developers, and art galleries from the books.
• The Hypertext d20 SRD  - Features the system reference document for the RPG game.
• Modernized! - D20 Modern Ezine  - Offers resources and guides for playing a modern-genre type campaign on the gaming system.
• Open Gaming Foundation  - Compiles SRD documents for the various gaming modules of the RPG system.
• PCGen  - Showcases a character generator for various RPG systems. Discusses technical requirements and provides resource links.
• RPGAttitude: D20 RPG Site  - Compiles tools and resources for both GMs and players including generators, game screens, and campaign and adventure seeds.
• Salon Technology: Dungeons & Dragons To Go Open-source  - Shows the interview with gaming executives about the rumors on RPG open-gaming licenses.
• Slashdot: Where Daemons and Dragons Collide  - Features resources and reference links of the open gaming source project that provides player guides and GM tools.