Created Worlds

Daleth
A steampunk world between fantasy, horror and science fiction. There are maps, detailed information and stories available.
http://www.xs4all.nl/~vanip/daleth

Domus Project
A fantasy world featuring a twin planet, ancient history and three different kinds of magic: the Spirit, the Fate and the Essaence.
http://www.niksula.cs.hut.fi/~juuso/domus/

Drak - The World of the Dragoncats
A medieval world with strangely modern devices. Several unique cultures and races, as well as an atlas, history, religion, and cultural entries.
http://www.lareau.org/drak.html

Geoza
A complete roleplaying environment created using the ARIA system. Features include Narrative Environments, an intricate Reality system, and several unique expansions such as an alternate system for handling psychic abilities.
http://www.geoza.com/

Kalyr
Here humans are a slave race, imported to an alien planet and overshadowed by several humanoid species. Maps, regions, languages, GURPS and Fudge conversions.
http://www.kalyr.com/kalyr.htm

Khoras
Forged from the fires of the Great War, the world of Khoras is reborn into the Age of Legends. It is a world haunted by the cataclysmic events of history and now left with a legacy of dark magic, lost legends, foul beasts bred for battle and long forgotten secrets waiting to be found.
http://www.khoras.net/

Lastaria, The Realm of
A game world based on Celtic and Norse Mythology.
http://www.geocities.com/TimesSquare/Ring/2665/

Maelstrom
An original campaign setting for all role playing games. Maps, cities, castles, floorplans, countries, deities, and heraldries.
http://www.geocities.com/TimesSquare/Fortress/6394/

Meln
Maps, cultures, religions, History, Calendar, Magic, Links. English/Finnish.
http://www.melnworld.com

Mythosa, Realm of
Mythosa is a fantasy world intended for use in a fantasy role-playing campaign. It is probably best suited for those systems that aren't tied to a prefabricated world (such as Advanced Dungeons and Dragons or Rolemaster), but it can be used for any system (RuneQuest, and Warhammer FRP).
http://www.mythosa.net/

The New Roman Republic
The former nation of Nova Sparta; still dedicated to a Classical Renaissance, with the rebirth of Ancient culture.
http://respublicanova.tripod.com/

Northlands, Welcome to the
Great but unknown forces stand to clash through the war-ravaged Northlands, but perhaps not all is lost. Come visit this beautiful, diverse world, and perhaps you will want to stay and change the course of history yourself.
http://www.geocities.com/TimesSquare/Realm/9675/

Sedes Draconis
A world built drawing on real science in biology, linguistics, geology, and astrophysics. (Not really a gaming world, though it started that way).
http://www.sedesdraconis.com/

Sheinar, The Confederacy of
Born out of a cataclysm war, the Confederacy of Sheinar is located on a archipelago that floats among the clouds. A campaign with aeroships, Plains Elves, and mysterious Dwarves.
http://members.tripod.com/LSidhu/

Sulerin
Hundreds of pages of original fantasy RPG material. Spells, magic items, rules, monsters, maps, and stories.
http://www.sulerin.com/

Telvar
A fantasy campaign world that has evolved over the last decade through the play of numerous characters. A virtual travelogue that allows visitors to wander and learn commonly known information about some of the countries of Telvar.
http://telvar.net/

Terèth End
A fantasy world for d20, Gurps, and Harnmaster roleplaying systems.
http://www.terethend.com

Terra Dyne
A Land of Magic and Adventure developed over 14 years.
http://www.geocities.com/Area51/6899/

TerraGloria
A d20 fantasy world campaign setting complete with maps, creatures, NPCs, history, and artwork.
http://terragloria.8m.com

Thee Atlas ov Testoria
Testoria is a campaign world for roleplaying adventures.
http://r4bid.net/LoreWeaver/Atlas/

Thystra
Home of Wulf the Freelance and other colorful characters, Thystra is a place of adventure, danger and humor.
http://wulf.freeyellow.com/

Tzalmir
The tyranny of Ghoras, lich-king of Tzalin, has come to a mysterious end. In the last century of his thousand-year reign, Ghoras' conquests had nearly realized his mad vision. an Empire to span the Six Thrones of the Six Gods. But then, as the expanding psychic shock of his death claimed each of his bile-wormed vassals in turn, the face of the Empire was irrevocably changed.
http://www.mit.edu:8001/people/boojum/tzalmir.html

Umbagollah
A fictitiously Peninsula set in the 10th century. Regional information with maps and history, and information about culture and custom of its inhabitants. Also features an online community with support for online roleplaying.
http://www.umbagollah.com/

Vale of Wizards
Anna's Fantasy Fudge. A campaign setting designed for high fantasy adventures. In other words, if the physics, geography and ecology is a bit on the dodgy side, you can put it down to magic.
http://www.moglit.demon.co.uk/rpg/world/wizvale.htm

Virtual Verduria
For scholars of Verdurian, RPG enthusiasts, tourists, and bemused spectators
http://zompist.com/virtuver.htm