This is a good point. I'm not that familiar with the bindings in ocaml. What I can say is that bindings should be written at an abstract enough level that they don't mess directly with internal bit representations. Using the ctypes library seems like a good way to go. If a bunch of libraries' bindings have to be rewritten because the internal runtime representation has changed... well then maybe that should be done once to allow them to be abstract enough so that future internal changes don't have the same impact.