Zsh distribution terms

[Zoltan Hidvegi <hzoli@xxxxxxxxxx>]

I had a correspondence with Richard Stallman about the zsh distribution
terms.  I would like to change the copyright notices in the C files
to something similar to the one he suggests below.  The difference will be
the copyright terms of the manual.  I'd like to place the manual under the
following copyright:

  Copyright (C) 1992-1996 Paul Falstad
  All rights reserved.

  Permission is granted to make and distribute verbatim copies of
  this manual provided the copyright notice and this permission notice
  are preserved on all copies.

  Permission is granted to copy and distribute modified versions of this
  manual under the conditions for verbatim copying, provided also that the
  entire resulting derived work is distributed under the terms of a
  permission notice identical to this one.

  Permission is granted to copy and distribute translations of this manual
  into another language, under the above conditions for modified versions.

These changes will make us easier to borrow code and documentation from FSF
sources.  After that we can freely use parts of FSF manuals in the zsh
manual.  To use FSF code we still have to ask for permission from the FSF
but it's more likely that we'll get it than without this change.

I think that this change just makes the copyright terms more clear.  I
always interpreted the copyright in that way.

Of course we need Paul Falstad's approval for this change.

Zoltan

----- Forwarded message from Richard Stallman -----

>From hzoli@xxxxxxxxxx Sat Aug 31 00:47:18 1996
Date: Fri, 30 Aug 1996 13:17:33 -0400
Message-Id: <199608301717.NAA04336@xxxxxxxxxxxxxxxxxxxxxx>
From: Richard Stallman <rms@xxxxxxxxxxxxxx>
To: hzoli@xxxxxxxxxx
cc: rms@xxxxxxxxxxxxxx
In-reply-to: <199608301540.RAA01642@xxxxxxxxxxxxxxxxx> (message from Zoltan
	Hidvegi on Fri, 30 Aug 1996 17:40:29 +0200 (MET DST))
Subject: Re: zsh distribution terms
Sender: hzoli@xxxxxxxxxx

    Where did you read that?  In the zsh-2.5 distribution?

I asked Badros to send me "the distribution terms of zsh"; I am not
sure which version he got them from.

     * Permission is hereby granted, without written agreement and without
     * license or royalty fees, to use, copy, modify, and distribute this
     * software and its documentation for any purpose, provided that the
     * above copyright notice and the following two paragraphs appear in
     * all copies of this software.

This paragraph is the one that has the problem.  The problem is that
it doesn't clearly say that people can distribute modified versions.

One can interpret it as giving permission for that.  It is a plausible
interpretation--but not absolutely certain.

I've encountered copyright holders who used such wording--and then
turned around, after the fact, to say, "Yes we gave permission to
distribute, and to modify, but we deny this means permission to
distribute a modified version.  You can distribute our version, and
you can modify it privately, but you may not distribute a modified
version."

Perhaps a judge would agree with our interpretation that this wording
implies permission to distribute a modified version.  But it is better
for the community if users can be completely sure what their rights
are.

I think you want to give permission to distribute modified versions.
So would you please add an explicit statement saying so?

For example, you could use this:

     * Permission is hereby granted, without written agreement and
     * without license or royalty fees, to use, copy, modify, and
     * distribute this software and its documentation for any purpose,
     * and to distribute modified versions of them, provided that the
     * above copyright notice and the following two paragraphs appear
     * in all copies of this software.

I see one other potential source of uncertainty.  It is not evident
just which texts "its documentation" refers to.  It cannot refer to
"anything that describes zsh" because anybody can write about zsh.  It
must refer to a specific set of documentation files.  But it doesn't
show what that set consists of.

I would suggest that the distribution terms for the software talk only
about the software; state the distribution permission for
documentation files in those files.  That way, people will know
precisely which works are covered by which terms.

----- End of forwarded message from Richard Stallman -----