[Interest] Qt free software policy

Thiago Macieira thiago.macieira at intel.com
Thu Aug 15 01:45:48 CEST 2019

On Wednesday, 14 August 2019 14:36:18 PDT Benjamin TERRIER wrote:
> Le mer. 14 août 2019 à 22:05, Thiago Macieira <thiago.macieira at intel.com> a
> écrit :
> > On Wednesday, 14 August 2019 12:17:44 PDT Benjamin TERRIER wrote:
> > > The new add-ons modules could be provided as GPLv3 + GPLv2 + LGPLv3.
> > 
> > Just a nitpick: there's no need to have GPL-3.0 and LGPL-3.0 at the same
> > time.
> > So the combinations are GPL-2.0+LGPL-3.0 and GPL-2.0+GPL-3.0.
> You are right.
> However; the KDE agreement explicitly states that Qt add-ons must be
> available under GPLv3.
> So I am wondering if there could be issues with licensing under LGPLv3 but
> not under GPLv3, even if for KDE it is equivalent.

LGPL-3.0 is the GPL-3.0 plus an exception, so it counts.

I haven't read the agreement in years, but last I checked it didn't specify 
which licence, only that it had to be open source. But I may be remembering 

> > I don't know if there's anything that is GPL-3.0 (without 2.0). There may
> > be.
> All recent and upcoming modules, except Qt 3D, are GPLv3, but not GPLv2.

I stand corrected. Thanks (and to Peppe).

> The reason I started this thread is that I needed an http server for a Qt
> project under GPLv2,
> I started to play with the QHttpServer (still work in progress, but working
> nice) until I realized
> I would not be able to use it because it is GPLv3 only.

I understand. This is the case when you have GPL-2.0 only code that you need 
to use. Even 12 years after GPL-3.0 there's still a lot of GPL-2.0 only out 

I wonder if there's a way to allow the GPL-2.0 & GPL-3.0 combination work, 
without allowing the reason that GPL-3.0 was chosen in the first place 
(bypassing the TiVo clause). Probably not, because that and the Patent clause 
are the reason why 2.0 and 3.0 are incompatible in the first place.

Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel System Software Products

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