This is the Debian GNU/Linux prepackaged version of mgetty+sendfax
Mgetty was written by Gert Doering <gert@greenie.muc.de>
or <gert@space.net>

You can find the source here:

  ftp://alpha.greenie.net/pub/mgetty/source/

This package was originally put together by:
    Nils Rennebarth <nils@nus.pan-net.de>
and was subsequently been maintained by:
    Christoph Lameter, John Goerzen, and briefly Paul Haggart
at which point Philip Hands <phil@hands.com> took over (Mid 1997).

Since version 1.1.22, mgetty (and vgetty) is distributed under the GNU
General Public License. On Debian GNU/Linux systems, the text of this
license can be found in /usr/share/common-licenses/GPL.

In the frontends directories (/usr/share/doc/mgetty/frontends/...):
  viewfax-2.5:
    Copyright (C) 1990, 1995  Frank D. Cringle <fdc@cliwe.ping.de>
    Distributed under the GNU GPL (see above)

  faxview-0.2:
    Copyright (C) 1994--1996 Ralph Schleicher <rs@purple.in-ulm.de>
    Distributed under the GNU GPL (see above)

  the "rs" utilities for Emacs:
    Copyright (C) 1995 Ralph Schleicher
    Distributed under the GNU GPL (see above)

  Many others whose distribution terms are explained in their source code...