just commented on mui github to opensource and maybe mui can replace zune.
MUI is mature

https://github.co...issues/258

MUI sources open would be nice because it would make it much more easy to update Zune. Unfortunately, as tboeckel already replied, morphos team member see mui as a property of the team and deny opening it. As far as I know was the creator of mui (stefan Stuntz) open but did not want to act against the team. So yes would be nice but will not happen

MUI 4 is already old, I don't know if they are needed but the sources for MUI 5 are available here:

Experimental Nightly Build Snapshots:
https://github.co.../snapshots

What is called MUI 5 now is from what I know based on a old original MUI source code snapshot. There were a lot of discussions if it was legal to develop it further and if they at that time not took something they were not allowed to. In any case the sources are not open and will not be open as long there is no permission from the morphos team. And that will never happen.