I started playing RPG's with a copy of the red box in 1983. Horror has been my favorite genre for many years, I run a homebrew Dark Conspiracy game every chance I get. SF and Fantasy are no strangers to me.
So far, I have posted two settings. First is Attwatta Preziv and the second is The Middle Lands of Keltor (both found on Homebrew Campaign Settings).
Attwatta Preziv is a Gamma World setting and it's very much a work in progress. I have expanded the setting to include a bit on surrounding towns, some regional history, gangs and organizations, a few new mutations, and a list of mutations compiled from other D20 games (Future and Apocalypse). I have added a section for regional rumors as a source for off the cuff adventures. There have been between 20 and 30 non-bot downloads a month for the past few months. I am happy to see people checking it out. I don't expect to update it much in the future as I think it has just about run its course. I may post my GM notes as soon as the game I'm running based on Attwatta is completed.
The Middle Lands of Keltor is a low magic, fantasy setting. I designed it for D&D 3.5 but it should work with Pathfinder as well. It includes a full color map, thousands of years of history, custom deities, and lots of room to grow. I may expand this setting in the future.
Any questions or comments can be directed to me via email, will dot gbn at gmail dot com.