If you mean active Fossil repos accessible over the web, there's Fossil itself (https://www.fossil-scm.org/index.html/doc/trunk/www/index.wi...), and SQLite (https://www.sqlite.org/cgi/src/doc/trunk/README.md). If you mean Fossil repo hosting, I know of Chisel but haven't used it and don't know anything about it. I don't think it requires much in the way of hosting though.

Edit: corrected SQLite URL.