In artic you wrote:

>Just to make things a little more complicated:  with MacOS-X, you
>run into a multiple-inheritance situation because it both is-a Unix  
>and is-a Mac...

   Platform
       KernelApi-Mac
            DisplayApi-MacClassic
            DisplayApi-MacCarbon

       KernelApi-Unix
            DisplayApi-X11
            DisplayApi-MacCocoa

       KernelApi-Win32
            DisplayApi-WinGDI
            DisplayApi-WinDirectX


-- Kapusniak, Stefan e