I noticed that there was an unofficial port of Haiku to PPC hardware, but I can’t seem to find a list of supported PPC computers for the port. Is there a good reference for this?
If it supported anything well enough to get past the boot screen, we would advertise it. It was initially developped for Max Mini (first generation), where it got to the boot screen but then stopped due to missing drivers. There was some effort to improve G5 CPUs compatibility after that, still without getting it to boot further.
The current efforts are on the SAM440 board, which is known to run MorphOS or/and AmigaOS. However it has at least the same issue, and possibly more.