Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Special Interest Groups
  3. Independent Developers
  4. Qt Commercial License Terms, Independent Developers
Forum Updated to NodeBB v4.3 + New Features

Qt Commercial License Terms, Independent Developers

Scheduled Pinned Locked Moved Unsolved Independent Developers
licensinglicenseindependentdevelopers
35 Posts 16 Posters 16.7k Views 2 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • J JonB
    24 May 2018, 07:36

    @luca
    Although I would not be encouraging you to not pay for Qt if you can:

    If you link dynamically to Qt, use only LGPL components, do not use private Qt modules or otherwise tinker with the Qt side, and there is nothing special about Android (I think it used to require static linking maybe, but not now) or whatever "app stores" you use, my understanding is that you do not need a commercial license.

    Basically, LGPL does not require you to publish your own source code when you link against an LGPL component, even if your app is commercial/you make money out of the LGPL usage. However, in my own case I use PyQt (Python binding to Qt), and that is GPL rather than LGPL, so I do have to make my source available if I distribute.

    All statements above according only to my understanding.

    L Offline
    L Offline
    luca
    wrote on 24 May 2018, 20:22 last edited by
    #21

    @JonB Thanks for the explanation.
    I would like to pay for a commercial Qt license to thanks for the good works THEY did, but at the moment it cost too much for free projects (non open source).
    The startup plan is not so expensive but it require you to pay forever if you publish your app in an app store.

    I hope Qt will find a good solution for all...

    A 1 Reply Last reply 24 May 2018, 23:42
    0
    • L luca
      24 May 2018, 20:22

      @JonB Thanks for the explanation.
      I would like to pay for a commercial Qt license to thanks for the good works THEY did, but at the moment it cost too much for free projects (non open source).
      The startup plan is not so expensive but it require you to pay forever if you publish your app in an app store.

      I hope Qt will find a good solution for all...

      A Offline
      A Offline
      ambershark
      wrote on 24 May 2018, 23:42 last edited by
      #22

      @luca

      I hope Qt will find a good solution for all...

      They did, LGPL. :) You can use that with a closed source free application on a web store as long as you link dynamically and Qt can be replaced easily with a version built elsewhere.

      Since you can now link dynamically on both iOS and android you should have no issues using the LGPL license for Qt. LGPL was made for your exact use case.

      Disclaimer: IANAL make sure to check with a lawyer.

      My L-GPL'd C++ Logger github.com/ambershark-mike/sharklog

      J 1 Reply Last reply 25 May 2018, 07:33
      1
      • A ambershark
        24 May 2018, 23:42

        @luca

        I hope Qt will find a good solution for all...

        They did, LGPL. :) You can use that with a closed source free application on a web store as long as you link dynamically and Qt can be replaced easily with a version built elsewhere.

        Since you can now link dynamically on both iOS and android you should have no issues using the LGPL license for Qt. LGPL was made for your exact use case.

        Disclaimer: IANAL make sure to check with a lawyer.

        J Online
        J Online
        JonB
        wrote on 25 May 2018, 07:33 last edited by
        #23

        @ambershark said in Qt Commercial License Terms, Independent Developers:

        Since you can now link dynamically on both iOS and android

        Ah, right, is that what I was thinking I recalled when I wrote

        I think it used to require static linking maybe, but not now

        ? Have they made it so you can now but didn't used to be able to? OOI, is that a change at the Android side or the Qt side to make it possible?

        A 1 Reply Last reply 25 May 2018, 08:20
        0
        • L Offline
          L Offline
          luca
          wrote on 25 May 2018, 07:54 last edited by
          #24

          Where can I find a list of LGPL Qt modules for a specific release of Qt ?

          1 Reply Last reply
          0
          • J JonB
            25 May 2018, 07:33

            @ambershark said in Qt Commercial License Terms, Independent Developers:

            Since you can now link dynamically on both iOS and android

            Ah, right, is that what I was thinking I recalled when I wrote

            I think it used to require static linking maybe, but not now

            ? Have they made it so you can now but didn't used to be able to? OOI, is that a change at the Android side or the Qt side to make it possible?

            A Offline
            A Offline
            ambershark
            wrote on 25 May 2018, 08:20 last edited by
            #25

            @JonB Pretty sure android always supported dynamic linking, although I could be wrong here, I'm not really a mobile developer. I've done one back end library on mobile and that was it.

            It was iOS that used to be static only and change to allow dynamic linking recently (like last year or 2).

            My L-GPL'd C++ Logger github.com/ambershark-mike/sharklog

            1 Reply Last reply
            1
            • C Offline
              C Offline
              Cheng shi hua
              wrote on 4 Dec 2019, 11:38 last edited by
              #26

              I am an independent game author. If I use LGPL, develop a library that uses QML and dynamically links QT, and then publish it to steam, do I need to pay QT or open source?

              J 1 Reply Last reply 4 Dec 2019, 11:44
              0
              • C Cheng shi hua
                4 Dec 2019, 11:38

                I am an independent game author. If I use LGPL, develop a library that uses QML and dynamically links QT, and then publish it to steam, do I need to pay QT or open source?

                J Offline
                J Offline
                jsulm
                Lifetime Qt Champion
                wrote on 4 Dec 2019, 11:44 last edited by
                #27

                @Cheng-shi-hua said in Qt Commercial License Terms, Independent Developers:

                do I need to pay QT or open source?

                No, as long as you can fulfill LGPL3 you do not need commercial license and do not have to open your source code.
                LGPL3 requires you to provide users the possibility to replace Qt libraries with their own versions. This usually requires you to provide object files (.o), so users can relink. And it is not possible when using static Qt libraries!

                Keep in mind people here (me included) are not lawyers!

                https://forum.qt.io/topic/113070/qt-code-of-conduct

                1 Reply Last reply
                1
                • C Offline
                  C Offline
                  Cheng shi hua
                  wrote on 4 Dec 2019, 12:34 last edited by
                  #28

                  No QT official came out to clarify? This matter is important

                  J 1 Reply Last reply 4 Dec 2019, 12:36
                  0
                  • C Cheng shi hua
                    4 Dec 2019, 12:34

                    No QT official came out to clarify? This matter is important

                    J Offline
                    J Offline
                    jsulm
                    Lifetime Qt Champion
                    wrote on 4 Dec 2019, 12:36 last edited by
                    #29

                    @Cheng-shi-hua This forum is for Qt users and not "Qt officials". If you want an answer from Qt officials then pleas ask Qt Company.

                    https://forum.qt.io/topic/113070/qt-code-of-conduct

                    1 Reply Last reply
                    4
                    • C Offline
                      C Offline
                      Cheng shi hua
                      wrote on 4 Dec 2019, 13:15 last edited by
                      #30

                      This is the case, thank you very much. Since it is a community, you can advertise here when I develop a game :)

                      1 Reply Last reply
                      0
                      • L Offline
                        L Offline
                        LarryCox
                        Banned
                        wrote on 15 Oct 2022, 04:14 last edited by
                        #31
                        This post is deleted!
                        1 Reply Last reply
                        0
                        • T Offline
                          T Offline
                          ThomasGrace123
                          Banned
                          wrote on 27 Oct 2022, 09:45 last edited by
                          #32
                          This post is deleted!
                          V 1 Reply Last reply 5 Nov 2022, 09:49
                          0
                          • T ThomasGrace123
                            27 Oct 2022, 09:45

                            This post is deleted!

                            V Offline
                            V Offline
                            vosob80267
                            Banned
                            wrote on 5 Nov 2022, 09:49 last edited by vosob80267 11 May 2022, 09:49
                            #33
                            This post is deleted!
                            1 Reply Last reply
                            0
                            • J Offline
                              J Offline
                              JamesPalmer
                              Banned
                              wrote on 5 Nov 2022, 13:38 last edited by
                              #34
                              This post is deleted!
                              1 Reply Last reply
                              0
                              • B Offline
                                B Offline
                                Betty R. Harris
                                Banned
                                wrote on 7 Nov 2022, 10:33 last edited by Betty R. Harris 11 Jul 2022, 10:35
                                #35
                                This post is deleted!
                                1 Reply Last reply
                                0

                                • Login

                                • Login or register to search.
                                • First post
                                  Last post
                                0
                                • Categories
                                • Recent
                                • Tags
                                • Popular
                                • Users
                                • Groups
                                • Search
                                • Get Qt Extensions
                                • Unsolved