Finally tried AROS

[falemagn]

This involves endianess problems in a way it is not possible map functions like OpenWindow() to the x86 AROS... making rendering calls to gfx lib is impossible because struct RastPort is not blackboxed and could have bigebdian pointers like the font, bitmap, layers, tmpras...

There'd be no endianess problem of any sort, as 68k programs would only be able to see the memory allocated for the emulator. It would work by mirroring any visual or otherwise state-changing operation on the native AROS, but still providing the 68k version of all structures to the emulated environment.

[falemagn]

it would be pretty much like running UAE, except the OS friendly 68k apps would run in such a way as to make it impossible for the user to know UAE was there...

It should be noted that this would be doable with any other host OS other than AROS itself. That is, you could start up 68k AmigaOS application, seamlessy, on any operating system where UAE runs, provided that the part which interfaces UAE with the host OS were adapted to each one of those OS's.