Thank you for telling me about these. I never heard of some of these and want
to try them out. However, they all have some issues. XPaint seems to come
closest to my dream application.
One of the biggest issues is with GNU paint and mtPaint: I am not aware of
any active maintainance of these projects. This means that there is nobody to
fix problems or add even minor features. You cannot go 6 years without any
issues without updates.
The rest of these all look pretty great, but only KolourPaint runs on
Windows. It looks pretty good to me. So, that is what I will go with for now.
Thanks once again for telling me about these.