AROS dominates the x86 scene. MorphOS dominates the PPC scene and AmigaOS dominates 68k scene. Where you see OS4 in this picture, I dont know.
I don't know what this OS4 Linux thingy is, but it is quite clear that all variants of AmigaOS from 1.x to 4.x dominate the AmigaOS scene.
It seems that after the migration of AmigaOS from 68xxx CPU to Power architecture it is said to die or already was dead. All the time. I'm a late adopter and jumped from AmigaOS 3.9 to 4.1 around 2009. It was to be said dead then. And it's still dying. Whohooo. And AROS dominates since then. Or will dominate. Some day. All platforms. Except those, where MorphOS dominates. Or was it vice versa?
Back to topic: Wow, very commited, Trevor. I wish you all the best and hopefully a somewhat calmer trip with this project(s) - especially regarding CPU availability.
