So we end now with a number of different incompatible implementations of MUI.
That trend has actually started with Zune...
Just because MorphOS refused to dump MUI and use Zune instead
Zune is not so "bad", as one compiled program usually can't run with Zune and MUI, as Zune and MUI (with the exception of AROS/m68k) are not binary/API compatible.
No AROS/x86 exe will call MUI5/MorphOS. No MorphOS/PPC exe will call Zune.
But for MUI/AmigaOS, MUI/MorphOS and MUI/aos3.x this can happen. An aos3/m68 exe usually runs in all three environments. But if the features of the three "MUIs" get more and more incompatible, things won't get any better.
Three MUIs on different architecture and different exe => programmer has to ensure compatibility
Different m68k MUIs, same 68k exe => *User* has the problems first!!
Well, if MorphOS drops m68 support in any future version, those problems are avoided then.