dfdisk is an utility that adds extra functionality to pkgsrc, allowing it
to fetch distfiles from multiple locations.  It currently supports the
following methods:

CD-ROM   The program manages a CD database where every disk is matched to
         a series of distfiles.  Whenever a distfile is requested, the
         program will check if it is known by the database and ask the
         user to place the needed disk in the drive.

Network  If a file is not found in the described database, the program
         fallbacks to the network, fetching the file from there (the usual
         method in pkgsrc).

Support for more methods may be added in the future, like for DVD-ROM.
