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Question about GPL

  • Qt frameworks is under LGPL license, it means that Qt users may create proprietary applications that
    dynamically link to the LGPL-licensed Qt libraries.

    I am not an expert on this area (licensing) so here is my question:

    Can you use GPL libraries (like e.g. GPL Report) in closed sources Qt applications by creating a module that uses the GPL library.

    For example:

    MyBussinessApp is a closed source application.

    MyReportLib is a GPL module, it uses GPL Report for example, and had one function that makes a custom report made by yourself.

    • printReport

    By using QLibrary class you load your library on runtime.

    /print button pressed/
    typedef void (*printReport)();
    printReport f_printReport = (printReport) QLibrary::resolve("moduleReport", "printReport");
    if (f_printReport)

    This way you can call a function from a GPL library on a closed source application without introducing GPL code with your app, and without
    linking your app to the GPL library.

    Does this infringe the GPL license ?

  • Moderators

    I am not a lawyer and jurisdiction is highly dependent on your country, but my understanding is that as soon as you load GPL code into your address space you are bound by the GPL.

    The authors of the GPL are not stupid, they know what they are doing! Don't assume that there are simple ways around the license.

  • Yeah, it would be too easy to get around the license. hehe

    Thanks for the answer.


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