Ron Johnston was prototyping the Mac user interface with a Unix kernel.
We all worked in total secrecy like the Color Mac folks were. That lasted a year or so, and then (Steve) Jobs found out about it and came to my office. And he wasn't happy. He says, ‘Ron, this project is done. ' And I said, ‘No, no, no, no. We have to have a more robust operating system for the Mac. The existing O/S does what it does, but it will never be able to do multitasking, proper security, or reliable networking. It was great to launch with, but we need a modern operating system to work with the new chips, and Unix is that it is a proven thing. He just looked straight at me and said, ‘No, there will never be a Mac on top of Unix. I forbid that. And he walked out.