Re: Overview of copyright issues

[Joseph Wakeling]

Hans Aberg wrote:
> I think that the formulation should be "GPL, v2 or latest", because
> otherwise those that want to redistribute the code can choose which
> version, which is not the intent - v3 is in fact more restrictive with
> respect to tivoization. Only one GPL should be applicable. The
> formulation "or later" is probably spilled usage when indicating which
> version can be used - then it means one can choose version.

The standard formulation, as advised in the GPL appendix which describes
how to apply the GPL to your programs, is

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

The whole point of this formulation is to give users of the program the
option to choose which version of the license they want to be bound by
if they redistribute or modify the code, and in particular to make it
easy for a project to upgrade the license OR NOT.

> This formulation also means that the distribution conditions may change,
> even though the copyright notice is not changed of a package, when new
> version of the GPL are issued. I think that is fully legal.

The problem with your formulation is that it is too restrictive.
Consider this scenario: a program is being distributed as 'GPLv2 or
latest' as you suggest.  Someone writes a GPLv3 program which links with
that code (as they are allowed to do at that point).  Now Version 4 of
the GPL is released.  Suddenly the person with the second program can no
longer keep linking to new releases of the first one, because 'GPLv2 or
latest' now means v2 or v4 and neither v2 nor v4 are compatible with v3.

It's a scenario that is completely undesirable.  'or later' basically is
about making sure that writers of programs using all future versions of
the GPL will have the right to link to or incorporate your code (as well
as being handy if, as a community, you decide you want to upgrade the
license).