COM has some simularities to GObject, IMO. What they did is they restricted themselves to the parts of the C++ ABI that are stable in practice. This is C expor

COM has some simularities to GObject, IMO. What they did is they restricted themselves to the parts of the C++ ABI that are stable in practice. This is C exports, C types, and the layout of classes and vtables. COM is entirely usable from C (although cumbersome). The layout of a COM class/interface just happens to be the layout of a C++ class or vtable.