Code attribution discussion

How do we deal with code attribution of twiki code?

This question has come up because of a copyright change in the EditTablePlugin topic, where I changed the prevously listed author Peter Thoeny to my own name (and adding "Copyright: © 2008, Arthur Clemens | Based on: TWiki:Plugins.EditTablePlugin © 2002-2008, TWiki:Main.PeterThoeny and TWiki Contributors").

It may well be that I went too far, as most posters on the mailing list stated, and if so I will change the copyright lines. But my main question is now: how? What is the good way to do it?

What is the good way to do attribution in general? I can see 2 issues:
  1. Currently we don't have a systematic approach of listing all contributors. Most code changes are not reflected in the copyright.
  2. The role of the "author" next or above to the "copyright" holder is not clear.

Code attributions is written as guidance how to deal with code attributions (specifically for permissive-licenced code, which actually resembles the way code is treated at twiki and here).

The first guidance is the recommendation to list all copyrights in one single file (generally called COPYRIGHT), instead of a file-by-file basis. TWiki has used a mixture: copyright notices in perl modules, and for extensions a copyright statement in an extension topic. The downside to file-by-file is that the lists are hard to maintain.

Currently only a few of the contributors of twiki code are listed at the copyright section. This cannot be with GPL as I understand it. We need to do a better job in tracking all the authors of a piece of code - which should not be hard because we can track changes from the last years from subversion.

When to decide if a code change is significant enough?

Most countries have adopted a very low standard of originality and creativity for copyrighted works, and even a few lines of code or the rearrangement of different sections of a project might be enough to cause the contributor to be a copyright holder.


What does "Author" mean? Main copyright holder? Core contributor? The currently active maintainer? The original writer, even if he left the code untouched for years?

And what happens to the author if the code is incorporated into this new project? I assume we need to make clear that code and plugins at our project are derived from the versions on

Also, for each author's protection and ours, we want to make certain that everyone understands that there is no warranty for this free software. If the software is modified by someone else and passed on, we want its recipients to know that what they have is not the original, so that any problems introduced by others will not reflect on the original authors' reputations.

To me this is conflicting, especially regarding the notice of "author" that assumes an active author (different from copyright). Having an author's name that is not actively working at the code, and even is not part of the project, is falsely suggesting that that person still contributes to the code.

Is "author" a twiki addition to the GPL requirements? I could not find any reference in GPL docs that the "author" must be mentioned. All texts only refer to having "copyright" attributions (which are multiple persons most of the time).


This very thin line is why several OSS projects ask their commiters to give the copyright to a single association/entity.

In this particular case, you share the copyright of the derivative work (if you change as much as a single line of code, is derivative work according to GPL). Keyword is share. In that sense, you must leave Peter copyright statement and add yours.

As for attribution, saying "Author: ArthurClemens, Based on: TWiki:Plugins.EditTablePlugin by PeterThoeny" should be enough.

I think that the way it is handle in the file should be ok for all intents and purpose:
# Copyright (C) 1999-2007 Peter Thoeny,
# and TWiki Contributors. All Rights Reserved. TWiki Contributors
# are listed in the AUTHORS file in the root of this distribution
# NOTE: Please extend that file, not this notice.
# Additional copyrights apply to some or all of the code in this
# file as follows:
# Based on parts of Ward Cunninghams original Wiki and JosWiki.
# Copyright (C) 1998 Markus Peter - SPiN GmbH (
# Some changes by Dave Harris ( incorporated
This should be enough for extensions.

For the core, I propose that we put a statement "the copyright is shared by all the contributors listed in the AUTHORS file" or something like that. Or, when the association is formed, the association could hold the copyright to the code, much in the same way it should hold the trademark.

Even then, the copyright statement should have a section stating the additional copyright to "Peter Thoeny, and TWiki Contributors. "

-- RafaelAlvarez - 08 Nov 2008 - 02:46

Once an author, always an author: if you write a book, you remain the author even if you never update it again. (If you wish to make it clear who should be contacted for support, then another field such as "Maintainer" should be used.) The author is the original holder of copyright, who can then assign the rights to others or grant licenses for copying. (Some copyright regimes specify certain rights that cannot be assigned, such as moral rights under Canadian copyright law.) As RafaelAlvarez says, in an open source project, it is typical for copyright to be assigned to the organization that is in charge of the project (or possibly to a benevolent leader). In addition to making it easier to list the copyright holder, it also simplifies enforcement of the license terms, as there is a single copyright holder to pursue legal action, as opposed to a huge number of individual owners (see the GPLv2 FAQ). For new submissions to the Foswiki project, since a non-profit organization is going to be formed, going this route is probably the best way.

The right to create derivative works is held by the copyright owner. The ownership of the derivative work is subject to whatever agreement is made between the copyright owner and the creator of the derivative work. My quick look through GPLv2 did not uncover any specific terms on who owns the copyright (the closest section I found was in section 2, in the paragraphs immediately following item (c), but this does not apply in this scenario). So it is up to each open source project to have a clear policy on how it wants to handle ownership of code submissions. In this case, with the fork not being an amicable one, it is probably safe to presume that the TWiki project will wish to retain its copyright over the snapshot of code from the time of the split.

-- IsaacLin - 08 Nov 2008 - 03:51
Topic revision: r6 - 25 Feb 2020, MichaelDaum
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