Like Unix, MTS had ideas that were ahead of its time, especially when compared to the other alternative OSes that were available for an IBM mainframe. Unfortunately for MTS, it ran on expensive IBM mainframes and Unix ran on cheap PDP-11s. As they say, the rest is history.

    Part of ‎Richard Stevens' answer to a question from his FAQ (http://www.kohala.com/start/rstevensfaq.html).