I OSX 10.5, have Intel Fortran, but I do not have Intel C, so need to compile OpenMPI using gcc, which is supposed to work.
When I run the configure script I get an error message about
configure: error: C and Fortran 77 compilers are not link compatible.  Can not continue.

I am guessing that the problem is that the Intel Fortran is compiling for a 64 bit architecture, and gcc is by default compiling for
32 bit.  I tried setting an environment variable CFLAGS=-m64, but this did not help.  I am really a novice at passing compiler
flags to things inside scripts, and also, not knowing these flags, and, also, maybe I tried to pass the wrong flag value.  I would appreciate it
if anyone who knows what to do could provide a very specific recipe for exactly what I need to do to fix this problem.
Thanks very much.  -bg