SCCS vs. RCS

[Eric Black]

In article <377 at mks.UUCP> wheels at mks.UUCP (Gerry Wheeler) writes:
>In article <580 at dsacg3.UUCP>, ntm1458 at dsacg3.UUCP (John Darby) writes:
>> [...]
>> 2. RCS is public domain.
>
>Is it public domain? I don't think so, but I don't have any hard
>evidence one way or the other. 

No, it is not public domain.  The author retains the copyright to
the code, but in the past, at least, has been quite liberal in giving
permission for using and/or distributing the code for no direct profit
(in other words, you can get permission to include it in a commercial
product as long as the product costs the same with it as without it).
Just ask him beforehand.

I quote the copyright notice contained in the source:

 * Copyright (C) 1982 by Walter F. Tichy
 *                       Purdue University
 *                       Computer Science Department
 *                       West Lafayette, IN 47907
 *
 * All rights reserved. No part of this software may be sold or distributed
 * in any form or by any means without the prior written permission of the
 * author.

Of course, Tichy is now at University of Karlsruhe, West Germany, at net
address <tichy%germany.csnet>.  I further quote from a letter he sent
me in November, 1987:

    If you received RCS via Berkeley Unix, then no further permission
    for distribution is required from my side.  I've also been informed
    that AT&T no longer claims ownership of diff and diff3, so you need
    not replace these components.

I interpret this to mean that if you had legitimate access to 4BSD sources,
then you have legitimate access to RCS source; this is not the only way
to legitimately get it.  I have not personally verified that AT&T has
abandoned claims to diff and diff3 source; unless this is so, then
legitimate access to sources for RCS, which includes files directly
derived from the diff and diff3 code for UNIX, requires the UNIX license.
Even if AT&T has not given away diff, then if those files are not present
in your collection of RCS sources, then you should be OK.  There are many
various versions of "diff" available; some hacking is required to make
any suitable for use in RCS, but it is apparently not necessary.

More from that same letter:

    However, there is a newer release of RCS, release 4.  This release
    is a much improved version, and upward compatibel [sic] with
    release 3...In addition, I now have a version of MAKE that is
    integrated with RCS.
    ...
    I can offer release 4 of RCS together with the new MAKE at a
    one-time fee of $5000 for a world-wide non-exclusive license.

I don't know any more (yet) about it.  We are looking into version 4,
and I'll post something when I do have more to say about it.

-- 
Eric Black	"Garbage in, Gospel out"
   UUCP:	{sun!sunncal,hpda}!athertn!ericb
   Domainist:	ericb at Atherton.COM