Named after its original programmer, GreyLine, glFtpD( greyline File transfer protocol Daemon) is one of the most popular FTP daemons in existence. It is highly configurable, runs chrooted, and also supports shell scripts. Though it can be configured to support any type of usage, it is generally used for ratio and "warez" servers.
glFtpD is available at
http://www.glftpd.org