NcFTPd is a fine ftp daemon... interQ uses it for both our consumer and corporate ftp applications. Mostly for users to upload their web pages.
I think the $199 fee per server is cheap for what NcFTPd features:
* easy installation w/o chroot tree necessary for anonymous ftp, /bin/ls, etc
* security -and- speed
* built-in quotas
* built-in QoS to limit incoming -and- outgoing bandwidth
* no-fork philosophy
An open, cross-platform journaling program.
A scientific plotting package.