cdfax is CD-ROM transfer tool that transfers
and burns CD-ROM data from one PC to
another over a network connection, much like
a fax machine.
MB-DiscID provides Ruby bindings for the
MusicBrainz DiscID library libdiscid. It allows
you to calculate MusicBrainz DiscIDs from audio
CDs, which you can use to find the release entry
for your CD in the MusicBrainz database.
A message transfer agent.
A simple DDNS client