ftpd-shadow-nis.tgz means that it is a ftpd server patched to work with
SHADOW suite and NIS.

Remark:
       if you have users with CSH default shell, don't forget to add:
               1) a link  /bin/csh  to /bin/tcsh (if /bin/csh not included)
               2) a line  /bin/csh   in /etc/shells.