Requirements for gnuplotfortran

This will work for any system that :

Provides popen, pclose, and other such functions. For instance, if you have the GNU C library installed it will do that.
C object files append an underscore to the end of C library functions.
You will need a copy of the LGPL'ed fortranposix library (Copyright (C) 2004 Madhusudan Singh).
Gnuplot. This library has been tested with GNUPlot 3.7.3 and version 4.0. It may not support all features of version 4.0.

The above means that most Unix like systems with Fortran 95 compilers can be tweaked to work with it. If you succeeded in porting gnuplotfortran and fortranposix to a new platform and/or compiler, let me know.