[Mingw-cross-env-list] Use of libX11

[Robert Funnell]

I have developed a fair amount of software that runs under both MS 
Windows and Unix. Graphics are done through a low-level 
system-dependent layer that is linked to either Visual Fortran 
routines (for Windows) or libX11 (for Unix). I would like to move away 
from MS Visual Studio and use Mingw instead. I now seem to have 
successfully used mingw-cross-env for the non-graphics stuff, but I'm 
not clear about what to do next, since libX11 isn't provided. Should I 
be looking at http://sites.google.com/site/xportmingw/?

(I have 10's of 1000's of lines of code that has evolved over decades, 
so converting to something like gtk is not a short-term solution, 
although it's on my to-do list.)

Thanks for any pointers you can offer.

- Robert