A few years back, a website called The Great Hundred was created. Its purpose was to collect encyclopedia-like articles written about fantastical topics. Originally, it was focused on a single setting (Rav, a land of god-kings and city-states) but there were plans for it to be a repository of more generic articles that could be slotted into any setting.
I think the Year of Living Free Wiki could use a project like that. Feel free to submit articles, descriptions and the like under any open licence you like (but they must be under an open licence).