*   Dennis Ritchie Ken Thompson

*   in the 1960's - MULTICS

*   Ritchie and Thompson wanted to play with
    some ideas from MULTICS in a smaller OS on
    a PDP-7 -->  UNICS
                 morphed soon after to UNIX

    *   originally written in assember,
        they wanted it to be more portable
	SO they developed the C language
	and rewrote the UNIX kernel in C

    *   UNIX was rewritten in C in 1972,
        and formally presented in a 1973
	Symposium in Operating Systems Principles

...

*  Linus Torvalds
   *   reverse-engineered a UNIX-like compiler
       and called it Linux
       *   In 1991, the Linux kernel was released

*  What makes UNIX, well, UNIX?
   *   POSIX - Portable Operating System Interface

   *   specified by the IEEE Computer Society, to define
       standards for maintaining compatibility
       between operating systems ...
       for software compatibility with variants of
       UNIX and other operating systems

   *   Linux is officialy "UNIX-like" because it met
       the POSIX standards for a "UNIX-like" kernel

*   READ the course syllabus!!

*   to read: skim the UNIX history section in
    (either version of...?) the course text
    *   [after class] ...in the 2015 version, the history section
        in the 2021 partial draft is blank...!