The guy who commented on being unable to use C++ for writing extensions is utterly wrong. You easily can. And you can also use Fortran, naturally, which is an invaluable asset in developing advanced extensions. You just need to know how ;-) Hint: RTFM on ABI, calling conventions, and features of your favorite link editor. And remember: you ALWAYS can call object code produced by compilers of other languages from C, ABI bridging is trivial, and in many cases simplified by the toolchain itself.