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--- publications:standards [2024/06/18 05:36] – segaloco
+++ publications:standards [2025/10/25 04:50] (current) – segaloco
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 ==== System V Interface Definition ====
+{{:publications:1985_svid_1.jpg?direct&200|1985 SVID Issue 1}}
 {{:publications:1986_svid_issue_2.png?direct&200|1986 SVID Issue 2}}{{:publications:1992_svid_issue_3.jpg?direct&200|1992 SVID Issue 3}}
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 The System V Interface Definition (SVID) is intended for use by anyone who must understand the operating system components that are consistent across all System V environments.  As such, its primary audience is the application developer who is building C language application programs having source code that must be portable from one System V environment to another.  A system builder should also view these volumes as necessary tools for supporting a System V environment that will host such applications.
+==== X/OPEN Portability Guide ====
+{{:publications:1985_xpg1.jpg?200|1985 XPG1}}
+{{:publications:1987_xpg2.jpg?200|1986 XPG2}}
+{{:publications:1989_xpg3.jpg?200|1989 XPG3}}
+The X/Open Portability Guide was initially published in 1985 and was derived from both the /usr/group standard as well as the SVID.  A few excerpts from the Preface to the first issue:
+The X/OPEN Group, formed in late 1984, is an initiative taken by major European suppliers of computer systems...[T]he Group defines a Common Applications Environment based on the interfaces to the UNIX operating system, and covering other aspects required of a comprehensive applications interface.  The Group has based its specification on the AT&T System V Interface Definition.
+Four versions of the XPG have been issued:
+  * Issue 1 - 1985
+  * Issue 2 - 1986
+  * Issue 3 - 1989
+  * Issue 4 - 1992
+XPG4 is the last and current issue and is a major influence on the IEEE 1003.1 POSIX standard and Single UNIX Specification.
 ==== POSIX/IEEE 1003 ====