Do we still need weak copyleft? (was Re: Exceptions to copyleft-next)

[Richard Fontana]

On Mon, Jul 20, 2026 at 10:12 AM Till Jaeger <till.jaeger at ifross.de> wrote:
>
> This is a case where the license incompatibility between GPL 3 and
> LGPL 2 really bit users in the *ss.
>
> Please don't get me started on that.  I sent an email to everyone
> with authority over the final text of GPLv3 at the end of the GPLv3
> process (but before it was released) pointing out that that it was as
> disaster that LGPLv2.1-only was incompatible with GPLv3.  Nobody
> cared except Richard Fontana.  See, there's a reason he and I are
> here 20 years later as the two working on this project, and everyone
> else involved in GPLv3 don't work on copyleft drafting anymore. 😆
>
> I'm not sure I understand this correctly.
>
> Sec. 3 LGPL-2.1 reads as follows:
>
> "You may opt to apply the terms of the ordinary GNU General Public License instead of this License to a given copy of the Library. To do this, you must alter all the notices that refer to this License, so that they refer to the ordinary GNU General Public License, version 2, instead of to this License. (If a newer version than version 2 of the ordinary GNU General Public License has appeared, then you can specify that version instead if you wish.) "
>
> Copyright owners using typical license headers as the following (from libnl)
>
> "* This library is free software; you can redistribute it and/or
> * modify it under the terms of the GNU Lesser General Public
> * License as published by the Free Software Foundation version 2.1
> * of the License."
>
> try to exclude the permission to "relicense" under the LGPL-3.0 but why should that exclude the permission to relicense under GPL-2.0 or GPL-3.0?
>
> Accordingly, I do not see a problem to link a GPL-3.0 licensed application with a LGPL-2.1-only licensed library by using the whole under GPL-3.0.
>
> Do you mean any other use case?

Maybe thinking of LGPLv3/GPLv2-only incompatiblity rather than
LGPLv2.1-only/GPLv3 ? This was an issue that was raised late in the
GPLv3 drafting process in mid-2007, I think particularly because it
was then anticipated that glibc might be relicensed to LGPLv3. I know
Bradley has in some past situations encouraged certain projects to use
LGPLv3|GPLv2 as a way to address this.

Of course, LGPLv2.x section 3 has almost never been literally complied
with by any project, but in FOSS folk-understanding it is seen as the
(or a) basis for intuitive LGPLv2.x/GPL compatibility.

Richard







>
> Best,
>
> Till
>
> _______________________________________________
> next mailing list
> next at lists.copyleft.org
> https://lists.copyleft.org/mailman/listinfo/next