Installing fax4CUPS is very easy:

0. Install efax (http://www.cce.com/efax/), HylaFAX (http://www.hylafax.org/)
mgetty-fax (http://www.leo.org/~doering/mgetty/index.html) or CapiSuite
(http://www.capisuite.de/). For HylaFAX you need also grep and sudo.

1. Install the man page.

2. Install the efax/hylafax/mgetty-fax/capisuite-fax scripts in the CUPS
back-end directory, for instance, /usr/lib/cups/backend/; you can look at
the first lines of the file for configurable parameters (the fax script is
provided for backward compatibility only).

3. Install the PPD files
efax.ppd/hylafax.ppd/mgetty-fax.ppd/capisuite-fax.ppd in the CUPS model
directory, for instance, /usr/share/cups/model, and create a new printer
using the a suitable back-end (see the man page; the fax.ppd PPD file is
provided for backward compatibility only).

4. Restart the CUPS daemon (usually "/etc/rc.d/init.d/cups restart" as root
will do the job).
