Ask HN: Where to learn about compilers and linking?

I'm an aerospace engineer whose work involves stitching together various codes to work together to solve coupled multiphysics problems. The problem is the different codes don't necessarily want to play nice together. For example, one of our codes supports the intel fortran compiler for custom user subroutines. Another only supports gfortran. Rather than fumble my way through just randomly trying various options to get them to play nice together, is there a good resource that I can use to learn more about what makes these compatible/incompatible and strategies for making modifications to get them stitched together in a reasonable manner (ie, not having each one do tons of text file I/O to pass loads and boundary conditions back and forth). It seems like between the various codes, I'm going to need to use a little C, a little Fortran, some python and some MATLAB depending on the particular analysis case.