Apple itself also had a project, started in the late '80s, to port the Mac OS to x86[2].
Incidentally, PowerPC Mac OSes, especially later pre-OS X OSes like Mac OS 9.x, run quite well today on vanilla QEMU, no hacking required.
[1] https://www.atarimagazines.com/startv3n6/mac_pc_on_st.html