Maybe as a little introduction? (Amiga)
"Tutorial: Writing an Amiga GUI program in C" written by Edwin van den Oosterkamp:
https://www.amiga-news.de/en/news/AN-2023-10-00017-EN.html
AmigaOne X5000 @ 2GHz / 4GB RAM / Radeon X1650 / AmigaOS 4.1 Final Edition / MorphOS 3.17
Amiga1200 / Blizzard 1230 IV PiStorm32-lite / 128 MB RAM / AmigaOS 3.9
