There was also OS9 (Microware, not Apple). It was very Unix-like, but not fully POSIX, and very poorly documented. After initial development on the 6809, they

There was also OS9 (Microware, not Apple). It was very Unix-like, but not fully POSIX, and very poorly documented. After initial development on the 6809, they released a port for 68K. https://en.wikipedia.org/wiki/OS-9 https://en.wikipedia.org/wiki/OS-9