Editing Single UNIX Specification (section)

===2001: Single UNIX Specification, version 3, POSIX.1-2001===
Beginning in 1998, a joint [[working group]] of IEEE, ISO JTC 1 SC22 and The Open Group known as the [[Austin Group]] began to develop the combined standard that would be known as the core of '''Single UNIX Specification, Version 3''' and as POSIX.1-2001. It was released on January 30, 2002.<ref>{{cite press release
  |url = https://unix.org/version3/pr.html
  |title = The Open Group announces completion of the joint revision to POSIX and the Single UNIX Specification
  |access-date = July 26, 2009
  |date = January 30, 2002
|publisher = The Open Group
}}</ref>

This SUS consisted of:<ref name=unixorgv3>{{cite web|url=https://unix.org/version3/overview.html|title=The Single UNIX Specification Version 3 - Overview|website=unix.org}}</ref>
* Base Specifications, Issue 6
** Base Definitions, Issue 6
** System Interfaces, Issue 6
** Shell and Utilities, Issue 6
** Rationale (Informative)
* X/Open Curses, Issue 4, Version 2
and is at the core of the UNIX 03 brand.<ref>{{cite web|url=https://www.opengroup.org/openbrand/register/xym0.htm|title=Open Brand - UNIX 03|website=[[The Open Group]]}}</ref>

The Base Specifications are technically identical to '''POSIX.1-2001''', which is IEEE Std 1003.1-2001.<ref name=unixorgv3/>

This version had 1742 programming interfaces.<ref name=v3howmanyapis>{{cite web|url=https://unix.org/version3/howmany.html|title=How many APIS are there?|website=unix.org}}</ref>

An authorized guide is available for the version.<ref>{{cite book|url=https://pubs.opengroup.org/onlinepubs/9299959899/toc.pdf|title=The Single UNIX Specification: The Authorized Guide to Version 3, 2nd Edition|publisher=[[The Open Group]]}}</ref>

====2004 Edition====
In 2004, a new edition of the POSIX.1-2001 standard was released, incorporating two technical corrigenda.<ref>{{cite web|url=https://www.opengroup.org/onlinepubs/009695399/|title=The Open Group Base Specifications Issue 6|publisher=[[The Open Group]]}}</ref><ref name=posix2004>{{cite web
  |url = https://unix.org/version3/ieee_std.html
  |title = IEEE Std 1003.1, 2004 Edition
  |access-date = July 26, 2009
}}</ref> It is called IEEE Std 1003.1, 2004 Edition.<ref name=posix2004/> Some informally call it POSIX.1-2004,<ref>{{cite web|url=https://docs.oracle.com/cd/E36784_01/html/E36883/posix.1-5.html|title=POSIX.1(5)|work=Oracle Solaris 11.2 Information Library}}</ref><ref>{{cite book|chapter-url=https://www.gnu.org/software/libc/manual/html_node/Feature-Test-Macros.html|chapter=1.3.4 Feature Test Macros|title=The GNU C Library manual|url=https://www.gnu.org/software/libc/manual/html_node/index.html|publisher=[[The GNU Project]]}}</ref><ref>{{cite conference|title=POSIX Abstractions in Modern Operating Systems: The Old, the New, and the Missing|conference=Eleventh European Conference on Computer Systems|doi=10.1145/2901318.2901350|doi-access=free}}</ref> but this is not an official identification.