This is an interface to a large part of the Xlib library.
There are a number of Makefiles here - the result can be rather confusing.

Makefile 
  Used if building the fptools libraries as part of the GHC build process.
  Requires that you have proerly configured the entire fptools/hslibs
  tree.  This is rather a complex business.

Makefile.ffi
  Used if building with a 'new' version of Hugs.  That is, a version 
  dated August 2002 or later.

  Typical usage:

    make -fMakefile.ffi
    make -fMakefile.ffi all
      Compile the three .gc files generating everything you need for use
      with Hugs.

    make -fMakefile.ffi X_dir=/usr/local/X11R6
      Same as above but override the choice of directory to search for
      libX11.so*
   
    make -fMakefile.ffi rerun_GC=yes
      Same as above but, assumes that 'greencard' is on your path
      and runs GreenCard first.

      You _must_ do this if you are building from a cvs source tree or
      similar distribution which lacks files with names like 
      Xlib_stub_ffi.c
   
Makefile.hugs
  This is a Makefile for use with the December 2001 release of Hugs.

  Typical usage:

    make -fMakefile.hugs system=SunOS X_dir=/usr/local/X11R6

  As with Makefile.ffi, you might have to specify rerun_GC=yes.
  You will also have to specify where your Hugs installation is
  (hugs_install=<wherever>) if it is not in /usr/share/hugs98.

Makefile.ghc
  This is an old Makefile for making Xlib with GHC without using the full
   GHC bootstrap environment.
  It is not known whether it works.

