Abrigon
Discussion list for an iron age setting in which supertechnology simulates the effects of magic.
ARWZ World
Alternative Reality Writer's Zone; Detailed fantasy and science-fiction worlds are created entirely by members. Anyone may join and add to the collaborative efforts in world creation.
Caeldera
The world of caeldera is being developed online by a group of volunteers.
Celandra - the Unyielding Land
A world in which 4 PBEMs occur simultaneously, in each the players play the role of societies, rather than single characters, and the purpose of the game is to plot the way of those societies through time, as well as to develop them and the campaign world further.
Dead Dragon Society
A community of game developers, authors, and roleplayers engaged in construction of a shared fantasy world for use with the d20 system. New participants are encouraged.
Dragons Breath, World of
A collaborative fantasy writing project. Features a library, character profiles, galleries, online comic, map, forum, and chat room.
Fargoth World Building Project
Features some nice maps, graphics and political information with original races, monsters, and flora and fauna. A generic gaming world for all systems. A mailing list is available for would-be collaborators.
Orion's Arm
A collaborative science fiction multi-race universe. Site contains numerous scientific, cultural, historical, and atlas entries as well as a beginner's guide, mailing list, FAQs, and community news.
Pisces
Site and message board for a collaborative world building project.
Qaiyore
Qaiyore is a continent in the world of Celandra: the Unyielding Land, a game world based on the Fudgified Interactive History (FIH) system. Players take the roles of societies, rather than playing individual characters. Emphasis is placed on developing a detailed history and cultures for Qaiyore, along with myths and legends.
Raieh Fractal Planet
Listings for geography, history, art, languages, and culture from various contributors. The site also hosts a fractal world generator, used in this setting's design.
Tabolport
Reference files for a fantasy city setting created by USENET contributors. Includes history, people, factions, and world notes.
The Santharian Dream - The Legacy to Tolkien'
Always wanted to develop a complete fantasy world in the style of J.R.R. Tolkien? Santharian excerpts, poems, maps - you're welcome in our realm!
The World
This is a collaborative environment for role-playing games. Players may design their own cultures, races, or religions and track how these interact with others' creations.
The World of Conclave
Draws from Oriental, African, Polynesian and other non-Western influences. Contains a beginner's guide, character journals, glossary of people, places, and things, and forums.
Unified Citizens of Earth
Finally end world government intervention through The Proclomation. Bring your persona. Now it's time to reinvent government and do it right.
WebWorlds - Project Coordination Site
The WebWorlds were set up to produce a shared multiverse that is designed to be as flexible as possible, no matter what sort of universe or dimension, heaven or hell, weird science or weirder magic.