Personally, I've been bouncing between several projects like a mink on methamphetamine:
- A sword-and-sandal setting for Cepheus Engine, since that ruleset gets lots of Science Fiction love and a lot less for fantasy RPGs.
- A pulp SF setting based on ideas from Fritz Leiber's "A Pail of Air" (which I discovered some time ago was in the public domain due to the peculiarities of American copyright law when it was published in 1951).
- An "open source" take on a Third Imperium-like setting as a way of giving back to--yet again--the Cepheus Engine community.
This is also besides thinking hard about trying to break out of my comfort zone and write a novel. Two possibilities there....
Needless to say, I'm not actually making much progress on finishing anything.
The main thing I am working on is still my Sword & Sorcery Dinosaurland setting Kaendor. Which is the current incarnation of a concept and set of ideas I started tinkering with 12 years or so ago. A young civilization of humans slowly spreading out into the vast wilderness that used to be the territories of a series of sorcerous inhuman empires that kept destroying each other and left behind numerous ruins from different eras that still hold old magic and treasures. Currently for Dragonbane, which I feel is exactly the kind of game system I've been looking for to really fit this setting for the last 10 years.
I also have a Space Opera setting in the drawer called Iridium Moons, which was inspired by Dune, Cyberpunk 2077, and Prey. A galaxy with an aetshetic similar to classic Star Wars and Dune where the entire exploration and colonization of new star system is being driven by the mining industry. Starships, space travel, and combat are based on early 20th century war ships and ocean liners, and the people in power are like old railroad magnates and oil tycoons who control their own planets like personal fiefdoms beyond the reach of state governments and run their colonies like company towns. But that's even more in the concept phase and doesn't have real content to run a campaign in yet.
Many years ago I wrote a "Vikings & Dinosaurs" setting for Pyramid magazine, and I think about re-visiting it every now and then. Thanks to Infinite Worlds' banestorm McGuffin, I was able to drop some medieval Norwegians into the South Pacific of a timeline with no K-T extinction, and since it was part of the IW setting you could even have modern-day time travellers drop in and join the party.