Previously, I wanted to make the Charon Prime standalone supplement, compatible with 0e and clones. However, now I plan to create two versions of the game. First one I want to do is a complete game, compatible with a ruleset already used in the Perilous Ages. Second (which I guess will be much more popular), will be of course compatible with most OSRish games / rules systems / whatever.
You probably wonder why I decided to create a version which most likely will be unpopular, plus will require much more time and effort to complete. The answer is simple - I want to run the game this way. Simple :)
I guess the next question is when - I do not know. Usually I work on several projects at the same time, which is not good in terms of publication time but - for me - is much better than focusing on just one setting and burn out relatively quickly.
More info soon. Next time, with more content.