Responding to a comment on the Docunext blog about pfSense and its FTP helper, I mentioned FTP Proxy.

I hadn’t visited the website for awhile so I stopped by just to refresh my memory when to my surprise the current maintainer has published two new releases. Awesome!

I emailed right away:

" Hi Andreas, I'd been looking for ftp proxy and when I found it several months ago I was thrilled. I noticed it hadn't been updated in awhile but I tried it out anyway and it did what I needed it to: proxy FTP users to different backend FTP servers based upon username, much like perdition does for IMAP users. I just noticed you've published two new releases and wanted to thank you for continuing to maintain the code. I'd like to make a suggestion and help implement it if I can: provide different backend mapping methods for selecting which backend to connect each user to. Perdition supports 1-to-1 mapping, but also supports regular expression matching. Another possibility would be a CDB hash database for super fast lookups. Thanks again for protecting this great project from bit-rot! - Albert"