I heard you can already build such a system yourself quite trivially by getting an FTP account, mounting it locally with curlftpfs, and then using SVN or CVS on the mounted filesystem

Brilliant :). Since this is currently going to woosh for younger visitors: https://news.ycombinator.com/item?id=9224

Great! I thought it was about this, and you saved me the time to look for the exact comment. Wow, 19 years ago... Time really flies.