why wont this compile ?
Bill, I suspect that there are very few users in this forum who use Fortran.
When you wish to compile a Fortran source file that contains USE statements, the corresponding module files must exist. These module files (*.mod) may be provided by Intel and be present in the compiler's include sub-tree; or, as in this case, you have to have generated the file plplot.mod when you installed or built the PLPLOT library.
By the way, the compiler didn't "crash", it ended normally, after notifying you of reasons for its inability to proceed.
xplt.f90(2): error #7002: Error in opening the compiled module file. Check INCLUDE paths. [PLPLOT] use plplot --------^