You missed MkLinux, but of the three (Copland, A/UX, and MkLinux), only one of those was ever slated to be the future of the Macintosh. A/UX was very interestin

You missed MkLinux, but of the three (Copland, A/UX, and MkLinux), only one of those was ever slated to be the future of the Macintosh. A/UX was very interesting, but it was also encumbered with a fairly expensive UNIX license and was never really a consideration as a replacement for the existing Macintosh System software. Neither was MkLinux.