Sorry, yes… I meant mtPaint v3.50 (although on
https://github.com/wjaguar/mtPaint
the README says …
“mtPaint 3.51 - Copyright (C) 2004-2021 The Authors”
I have tried out the process from the Handbook…
9.Animation
Once you have created an animation you are happy with, you can create an animated GIF using the following steps:
• Load the original image, in order to clear the undo history.
• Set up the palette shifter with the values you want, and using the play button to preview the results.
• Press the 'Create Frames' button and close the palette shifter window.
• Undo one frame by pressing Ctrl-Z.
• Select 'Export Undo Images' from the File menu and place the files in a new directory somehwere using the filename 'out'. Make sure you select the GIF file type.
• Load one of these undo frames such as out001.gif.
• Select 'Export Animated GIF' from the File menu and choose a suitable filename and delay.
…on my Mac under Wine and it does indeed work!