r.in.tiff / r.out.tiff Requirements:

  TIFF library:
    libtiff:
	     http://www.libtiff.org/
             (old) ftp://ftp.sgi.com/graphics/tiff/
             (old) http://www-mipl.jpl.nasa.gov/~ndr/tiff/
         
  ZLib compression library:
    zlib:  ftp://ftp.cdrom.com/pub/infozip/zlib/zlib.tar.gz
           ftp://ftp.uu.net/graphics/png/code/
           ftp://ftp.uu.net/pub/archiving/zip/zlib
    The zlib home page is http://www.cdrom.com/pub/infozip/zlib/


Usually these libraries should be installed on your machine.
Otherwise get the source code and compile them.
