[takeda]

I think that's AROS[1].

When trying to remember its name I also found Apollo OS[2].

[1] https://amigang.com/software-aros/

[2] http://www.apollo-computer.com/apollOS.html

Edit: Looks, like Apollo OS is a fork of AROS that is optimized to run on the original Amiga hardware.

[vidarh]

ApolloOS is optimized to run on "680x0" hardware, including the FPGA based Vampire accelerators (and presumably the standalone Amiga replacement). So while it will run on original Amiga hardware, it also has optimisations that are Vampire specific (extra instructions etc.)

[takeda]

I see, thanks for the explanation.