Habisfern - A campaign world which was designed along with Yags, so fits that game system pretty well. A fantasy setting, without a multitude of character races.

The Land of Kythe - Originally an AD&D setting that was converted to my own system some years later. It was in use from about 1989 to 1995.

Mortals - A science fiction setting in the far future, where humanity has taken control of its destiny and has colonised the stars.

The One Time - A universe spanning network of wormholes linked together by relativity and time dilation into a single time spanning billions of years. For humanity though, there is no future.

The Midnight Saga - An Ars Magica saga set in Mythic Europe. This campaign is currently active.