Since the current versions of x11 on the Mac are no longer supported, the standard Graphics module doesn’t work. I noticed on GitHub development of a Cocoa based version. Is it available? Does it work?
Do you mean https://github.com/nojb/ocaml-graphics-osx? As far as I remembered it never got past the point of experiment; one issue I remember was that the UI needs to run in the main thread under OS X, which affected the API of the library.