[Interest] Qt free software policy

David M. Cotter dave at kjams.com
Wed Aug 14 19:00:06 CEST 2019

+1 on this

i am in the process of porting my legacy project to Qt and am afraid that i’ve made the wrong choice.  i’m just one guy and i bet my whole business on the availability of what  i need from Qt under LGPL

i’m already using a third party HTTP server so i’m not affected by this but it’s a worrying sign. I too agree that the HTTP server really should be LGPL.

What’s going to happen? It’s taken me over a year’s worth of work to get this far with Qt and i’m only half done. did i make the wrong choice? 


> On Aug 14, 2019, at 9:18 AM, Benjamin TERRIER <b.terrier at gmail.com> wrote:
> Hi everyone,
> Since we are talking about the future of Qt these days, I would like
> to know The Qt Company free software policy with Qt.
> Today, most of Qt modules are released under 3 free software licenses: LGPLv3,
> GPLv2 and GPLv3. Some modules are released only under GPLv3.
> If my memory is good, these GPLv3-only modules are the ones which used to
> be commercial-only modules (like Qt Charts).
> However, it seems to me that most, if not all (except Qt 3D), new Qt modules
> are now being released only under GPLv3:
>  - Network Auth
>  - WebGL
>  - WASM
>  - Http Server
>  - Lottie
>  - Quick 3D
>  - MQTT
> I understand that The Qt Company is only obligated to release new modules
> under GPLv3 (because of the KDE agreement).
> I understand also that The Qt Company business model is selling Qt licenses
> and has no direct financial interests in releasing Qt under any other license.
> So I can understand that some modules, in particular those valuable for wealthy industrial companies,
> are only released under GPLv3.
> However, for some modules like HttpServer, it seems to be an odd choice. There are plenty
> alternatives available under LGPL or more permissive licenses, so I do not see what 
> would be the loss of releasing it under LGPLv3.
> Also the fact that those modules are GPLv3 only is a problem when developing with other
> components that are GPLv2 only (and not GPLv2+).
> So I would like that someone could officially confirm if all new modules will be 
> released under GPLv3 only. Or if it is something that is decided on a per module
> basis.
> I believe that Qt users and contributors deserve to know what it The Qt Company
> view on this.
> Using an LGPLv3 framework is not the same thing as using a GPLv3 framework
> where some historical parts are available under LGPLv3 and all new features will be GPLv3 only.
> BR,
> Benjamin
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