So, I started the ball rolling. Wrote up a questionnaire for everyone in the group to fill out, asking all kinds of questions about what kind of campaign they want to play, etc etc. As the answers started to drift back to me, I got to work...
This is basically an entire campaign setting that I'm building completely from scratch. I thought people might be interested, in the "ant farms are interesting" sense of the term, to see a campaign setting built from the ground up. I'm not currently soliciting for help, so really it's not a Wiki in the true sense of the word at the moment, as I'm the only one who has write access.
With the exception of that first page (the overall setting info math, such as diameter of the planet and so on), all information presented in the wiki is only the stuff that is either relatively common knowledge to the location the campaign is starting in, or that the PCs have discovered. Since the game hasn't started yet, the PCs havn't discovered anything yet. This means, among other things, that it's almost completely system neutral, as there are no game stats anywhere on the campaign setting section of the wiki (nor will there be).
The world concept itself is based strongly on the old D&D Mystara campaign setting, although I have not yet decided whether the world is hollow. The information in the wiki is presented in much the same way that information was presented in the Poor Wizard's Alamanac supplements for the Mystara campaign setting, although I'm not limited by printing concerns so I can go into much more detail. Atlacia also draws on work I've done for games, novels, and campaign settings that I've worked on in the past (all unpublished, to date).
Anyway, people are more than welcome to watch it get built, comment on and discuss any parts of it, or borrow it for their own home games. I do reserve copyright on it, however, so no trying to claim it for your own (not that I think anyone would do that, but it has to be said).