Any D function marked as extern(C) can be called from C. As long as you have a C header file defining the functions and the appropriate C declarations any custom types you have, the C code will have no idea it's calling into a D library.
Thanks for the example. It clarify things up. The druntime is just another dynamic library file I need to supply with my software. And I have interest in not statically linking it since the main program and the libraries will each need a copy of druntime.
So it's more the cross-compiling that could remain an issue, but it does not seem that much more complex than it currently is with gcc and mingw.
I guess I'll need to do some R&D for both D language and Raylib.
