Look at the make-all script to make sure things are the way you would
like them and then invoke the script with either "make-all single" or 
"make-all double" to make the appropriate library.

I've written two sets of stub routines (for Data General UX and
IBM AIX) that allow Fortran programs to call the plplot library.
You might be able to modify (or even use one set as is) for use
on your machine. These routines are available in a separate tar
file (not included with this distribution).

These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.