Warner Losh wrote in
 <CANCZdfpSPE0yhgyFch4JDUC1JW17V4pz7cZ2aGpDk+chsY93ig@mail.gmail.com>:
 |I'll add that POSIX, as we know it today (and really since at least 2000)
 |is a collaboration between The Open Group, IEEE Std 1003.1-XXXX and ISO/IEC
 |9945:YYYY (collectively known as the Austin Group, though why "Austin" I
 |cannot say).
 |
 |So these days, it's standardized by "both" IEEE and ANSI (in the form of
 |ISO, of which ANSI is effectively a member).

The explanation is part of the standard

1
  The Austin Group is named after the location of the inaugural
  meeting held at the IBM facility in Austin, Texas in September
  1998.
2
  The name POSIX was suggested by Richard Stallman. It is expected
  to be pronounced with the first two syllables as in positive,
  not poh-six, or other variations. The pronunciation has been
  published in an attempt to promulgate a standardized way of
  referring to a standard operating system interface.

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)