OpenBSD supports sparc very well and is compatible with old sunos stuff (iirc). Unfortunately no 68k anymore (okay, technically there's a niche flavour of 68k that still is supported because of a very dedicated man in Japan)
No 32-bit sparc anymore (only UltraSPARC, aka sparc64).
No SunOS compatibility (despite Theo de Raadt inventing it for NetBSD, before being copied by other BSDs).
https://marc.info/?l=openbsd-tech&m=161435521906992&w=2
> Technically there's a niche flavour of 68k that still is supported because of a very dedicated man in Japan
luna88k, while related, is not 68k.
https://www.youtube.com/watch?v=btwiiZw3B2s
Kenji Aoyama truly is aligned with the best of the hacker spirit. As for getting your hands on a luna88k, I have no clue. The only thing I managed to find was a broken one that sold for ~USD 750 at an online auction.
http://miod.online.fr/software/openbsd/stories/m88k.html
One interesting bit of trivial is Luna-88k workstations were heavily used to implement CMU Mach (which would eventually be used by Apple).
>luna88k, while related, is not 68k
I misremembered it as being similar to the relationship between the 6502 and the 65C816