Right, though a LAPACK implementation is probably going to be mostly Fortran from the reference version, typically with some optimized routines, e.g. what OpenB

Right, though a LAPACK implementation is probably going to be mostly Fortran from the reference version, typically with some optimized routines, e.g. what OpenBLAS imports. Something to note is that unfortunately, the interface is the obsolete Fortran77-style, not modern Fortran, though that does make it more likely you can interchange implementations at run time as appropriate.