instability in Berkeley versus AT&T releases

[Doug Gwyn <gwyn>]

> System III.

UNIX 3.0

> System V, consider it standard.

UNIX 5.0 (4.0 was not released for public licensing)

> System V, release 2, from now on consider it standard.

UNIX 6.0, until AT&T decided to establish "UNIX System V" as
a recognized symbol.  Now UNIX 5.2

> System V, release 2, Version 2?

This has been a remarkably upward-compatible evolutionary path.
5.2.2 added demand paging (much cleaner than 4BSD's) and
record locking (more general than either 4BSD or /usr/group)
without visibly changing the semantics of already-existing
facilities.  This is the way it should be.

Both 4BSD and UNIX System V have good and bad points and both
have unnecessarily broken things in new releases.  The main
advantage of System V (notice that "UNIX" is omitted here)
with regard to stability is that all significant commercial
UNIX and C standardization efforts are adhering closely to it
(and vice-versa).

Could we go on to more productive topics?