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What modules are under what license?



  • Hello,

    I was thinking about using PySide2 for designing my application which I may sell commercially.

    I choose PySide2 as it is LGPL licensed but I realized that PySide2 is using Qt components, some of which are GPL licensed, others are LGPL licensed?

    I am confused, there is no direct information available about this on the Qt website.

    Can I use them without having to buy a commercial license and without releasing the source code? If yes, which components are LGPL licensed?

    I don't have a problem buying the commercial license, but the price is too high. I live in a very poor third world country and if I want to purchase the license, I will have to sell my business and use that money to buy a license.


  • Moderators

    Each module has license information in it's main documentation page. For example:

    Generally speaking, all "old" modules (QtCore, QtNetwork, QtWidgets, QtQuick etc.) are under LGPLv2, LGPLv3, GPLv2 and GPLv3 (you can choose which one you want). Most new modules (QtCharts etc.) are available under LGPLv3, GPLv3. Plus commercial, of course.



  • @sierdzio said in What modules are under what license?:

    Each module has license information in it's main documentation page. For example:

    Generally speaking, all "old" modules (QtCore, QtNetwork, QtWidgets, QtQuick etc.) are under LGPLv2, LGPLv3, GPLv2 and GPLv3 (you can choose which one you want). Most new modules (QtCharts etc.) are available under LGPLv3, GPLv3. Plus commercial, of course.

    Thanks. I am only using QtCore and QtWidgets.

    I see that you mention that they are available under "LGPLv2, LGPLv3, GPLv2 and GPLv3". What does that mean? They have multiple licenses available and I can choose whichever I want? If yes, how exactly do I "choose" whichever I want?

    Also, if I use QtCore and QtWidgets under LGPL to make my small application, if I do decide to sell it, will I have to purchase a commercial license from Qt?

    If yes, I have to purchase commercial license, is there any way to reduce the price? Cause my business won't be able to afford such a high price.

    Sorry if these questions seem really newbie, I am in fact a newbie to the world of licensing.


  • Moderators

    @lolcocks said in What modules are under what license?:

    @sierdzio said in What modules are under what license?:

    Each module has license information in it's main documentation page. For example:

    Generally speaking, all "old" modules (QtCore, QtNetwork, QtWidgets, QtQuick etc.) are under LGPLv2, LGPLv3, GPLv2 and GPLv3 (you can choose which one you want). Most new modules (QtCharts etc.) are available under LGPLv3, GPLv3. Plus commercial, of course.

    Thanks. I am only using QtCore and QtWidgets.

    I see that you mention that they are available under "LGPLv2, LGPLv3, GPLv2 and GPLv3". What does that mean? They have multiple licenses available and I can choose whichever I want? If yes, how exactly do I "choose" whichever I want?

    You simply decide to pick one of them, and then fullfill all license obligations (for example, simplified rundown of LGPLv3). That's enough.

    Unless you choose commercial, then of course you need to also pay Qt Company some cash, register etc.

    Also, if I use QtCore and QtWidgets under LGPL to make my small application, if I do decide to sell it, will I have to purchase a commercial license from Qt?

    No. *GPL licenses do not prohibit selling of stuff, they are concerned only with availability of the source code. You just have to fullfill license requirements, that's all.

    If yes, I have to purchase commercial license, is there any way to reduce the price? Cause my business won't be able to afford such a high price.

    There is a startup license, see Qt blog.

    Sorry if these questions seem really newbie, I am in fact a newbie to the world of licensing.

    No problem, I'm happy to help. With the usual disclaimer that I'm not a lawyer, I'm not an employee of Qt Company etc. Don't treat my replies as definitive 100% correct answers :-)



  • This "matrix" view is helpful. It lets you filter modules by "License Model" (a drop-down on the side). I bookmarked this because it is really hard to find in a search for some reason: http://www1.qt.io/licensing-comparison



  • @sierdzio said in What modules are under what license?:

    Most new modules (QtCharts etc.) are available under LGPLv3, GPLv3. Plus commercial, of course.

    We would very much have liked to use QtCharts, but have had to reject it as not LGPL but only GPL. Your referenced page for this, https://doc.qt.io/qt-5/qtcharts-index.html#licenses

    Qt Charts is available under commercial licenses from The Qt Company. In addition, it is available under the GNU General Public License, version 3.

    Could you kindly clarify whether I have misunderstood and QtCharts is available under LGPL, as that would be a shock to us?!


  • Moderators

    You're right, QtCharts are not available under LGPL.



  • @sierdzio

    Thank you for all your help kind sir. You have answered a lot of my questions.

    Now considering all the license, I should go and have a word with my boss about release the source code so that we don't land into any trouble.

    Quick side question, does anyone know if I will have to release the entire source code (including the proprietary one) or just the part of it that is using PySide2?
    I will be option for LGPL obviously.


  • Moderators

    @lolcocks said in What modules are under what license?:

    @sierdzio

    Thank you for all your help kind sir. You have answered a lot of my questions.

    Now considering all the license, I should go and have a word with my boss about release the source code so that we don't land into any trouble.

    Quick side question, does anyone know if I will have to release the entire source code (including the proprietary one) or just the part of it that is using PySide2?
    I will be option for LGPL obviously.

    I don't know if PySide has any additional rules or licenses. For the Qt itself: if you fulfil LGPL obligations, you do not need to publish source code of your application.


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