>
> 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).
>

Because IBM hosted the first meeting in Austin, at their Unix development
center.  Check out the footnotes at
https://www.filibeto.org/sun/lib/standards/susv3/frontmatter/preface.html