CC: gert@greenie.muc.de (Gert Doering)

For data only, no other software is needed.

mgetty itself can only send or receive G3 (raster) format.  However,
the distribution includes tools to convert raw G3 files to or from the
format used by "pbmplus", the Portable Bitmap Toolkit.  The pbmplus
formats support (or are supported by) most raster-image programs and
file formats generally used in the Unix world.  pbmplus is available
at this URL (among others): 

  ftp://sunsite.unc.edu/pub/X11/contrib/pbmplus10dec91.tar

The mgetty+sendfax distribution contains a patch to fix pbmplus's
broken pbmtog3 converter -- using the unpatched pbmtog3 can cause
errors during transmission. 

GhostScript, the free Postscript page description language
interpreter, can convert PostScript to G3.  Ghostscript is available
at this URL (among others): 

  ftp://sunsite.unc.edu/pub/gnu/applications/
     (also check out patch files in same directory.)

Hp2pbm, available from ftp:// ??, can convert text and PCL (HP
Laserjet language) to G3 or PBM.  It also contains programs for
converting PBM to PostScript, PCL and Epson printers.

PBMPLUS has converters from most existing raster formats or ASCII
to PBM, and from PBM to most raster formats.  You'd use the pbm2g3
and g32pbm utilities in mgetty to convert between PBM and G3.

In essence, you can run with hp2pbm or PBMPLUS alone.  With GhostScript,
you also need PBMPLUS or hp2pbm to convert ASCII (used for page headers
etc.) to G3.

Mgetty+sendfax includes some voice processing utilities in the voice/
subdirectory. These tools (pvftools) can convert ZyXEL, Rockwell and
ISDN4Linux voice formats. Other formats are coming. People reported
success in translating GSM encoded voice formats, so support for that
will also be added in the future. This means that vgetty currently
supports the three above and support for more modems is planned.