"The best" depends largely on what you want. If all you want is a
updater for the DEF files it's easy to write or use a simple batch
file for either FTP.EXE or for the internet file fetcher WGET.EXE.
If you want auto-updating of new versions, it's a bit more involved
since a program must be used which can analyze the contents of the FTP
site and keep track of version numbers. My web site offers a free
proggy to do just this. It also offers a more elaborate proggy which
does quite a bit more ... the F-Pup download.
There have been other F-Prot for DOS updaters available as well. I
have no idea as to their current availability or features. Some have
allowed for user selection of FTP sites whereas my updaters currently
use only the FSI primary FTP site.
Art
http://www.epix.net/~artnpeg