I've written a novel FTP server named publish-ftpd that's meant to do something different from run-of-the-mill FTP servers. It provides each user (which shouldn't have any connection with the server's password file) a read-only subtree of files under password control. It's not high-security (the files can be snooped) or high-performance; it emphasizes protocol correctness -- users can't escape their home tree.
I'd appreciate reviews of the documentation even from people who don't want to run such a thing. Actual reviews of the program are of course useful too.