In the early 1980's I worked at the University of Toronto Computing Service, a typical university mainframe shop. My boss at one point was Terry J. Wood, a very forward-looking individual and a great mentor to me at the time. We were very aware of the potential impact of micro-computers, having built a student access system upon the DEC LSI-11/23. One of the issues of the day was IBM's per-CPU licensing for systems and applications, so one of our favorite questions to ask visiting academics was something like: "So what will per-cpu licensing really mean, when you can emulate an entire System/370 in a hand-held computer?"
When I got Hercules, a free, open-source System/370 emulator and freely-downloadable VM/370 and OS/370/370 going on my Mac notebook, I knew that our prophecy had, like those of MacBeth's witches, come true to the max.