glFTPd

http://en.wikipedia.org/wiki/Glftpd

glFTPd is a freely available FTP server which runs on Unix, Linux, and BSD operating systems. It has number of features, like logins restricted by a particular set of IP addresses, transfer quotas per-user and per-group basis, and user/groups not stored in the system files, which make it attractive to private warez servers, including topsites.

Websites

http://glftpd.eu/
http://www.glftpd.dk/

Scripts

http://www.pzs-ng.com/
http://www.grandis.nu:81/glftpd/scripts/
https://github.com/glftpd-scripts/glftpd-scripts

Installation guides

http://www.mewbies.com/how_to_install_glftpd_tutorial.htm
http://nixbits.net/wiki/doku.php?id=setup_and_configure_glftpd