Qt Forum

    • Login
    • Search
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Groups
    • Search
    • Unsolved
    1. Home
    2. Tags
    3. lgpl

    Log in to post
    • All categories
    • D

      Unsolved LGPL distribution in the Microsoft Store
      Installation and Deployment • licensing lgpl windows 10 microsoft uwp • • daljit97

      7
      0
      Votes
      7
      Posts
      629
      Views

      sierdzio

      @daljit97 said in LGPL distribution in the Microsoft Store:

      @sierdzio I suppose that could be an option I could consider, although I worry about piracy concerns.

      Well, either worry about that or about Qt license costs. If you break the LGPL then you become the pirate ;-)

      In this setup, if somebody gets the exe from you, they have already paid you. It does not solve the piracy problem, but does limit it somewhat.

    • L

      Unsolved Qt and closed source, commercial development
      Mobile and Embedded • licensing embedded lgpl commercial closed source • • luisfilipels

      7
      0
      Votes
      7
      Posts
      1126
      Views

      M

      You can use this app template:
      https://marketplace.qt.io/products/qt-lgpl-app-template
      Offers you a relink mechanism, also for embedded devices:
      you can release a redistributable project (your application inside a compiled static library, in a qt .pro project)
      and you must release your SDK (sysroot and compiler).
      If you use Static Qt, user can build his own Qt and rebuild your closed source application.

    • S

      Solved LGPL and Qt Meta-Object Compiler outputs
      General and Desktop • license lgpl gpl moc • • Soga

      3
      0
      Votes
      3
      Posts
      609
      Views

      S

      @SGaist Hi, Thank you for your reply. I understand your point, so I set this topic solved.

      I just realized that C:\Qt\Licenses\LISENSE do not include the GPL v3 exception stated above. Hence, the argument above does not hold.

    • T

      Unsolved How to comply with LGPL on Android
      Mobile and Embedded • android lgpl • • Tom_H

      3
      0
      Votes
      3
      Posts
      944
      Views

      M

      You can use this app template:
      https://marketplace.qt.io/products/qt-lgpl-app-template
      The user can download the redistributable project, rebuild it and upload it to their own device (using the Android SDK)

      You just need:
      -a web server to store redistributable project and Qt sources
      -an about dialog with all licenses

    • Matthew11

      Solved LGPL license and "open" consumer device obligation with embedded.
      General and Desktop • lgpl licensing embedded applic • • Matthew11

      4
      0
      Votes
      4
      Posts
      1438
      Views

      Matthew11

      Some time ago Qt published webinar concerning the topic, which helped me a lot.

      I am adding a link for future readers: https://resources.qt.io/videos/complying-with-the-requirements-of-the-gpl-lgpl-v3-license-on-demand-webinar

    • CAD_coding

      Solved Can I hyperlink source code of Qt instead of distributing it with my installer?
      General and Desktop • licensing lgpl source code installer • • CAD_coding

      12
      0
      Votes
      12
      Posts
      3679
      Views

      A

      @Eeli-K That would mean you can't use github at all then since it isn't under your control. If github is considered "under your control" you can just fork Qt to your github account though.

      I mean along these lines though no web server you don't actually own is truly under your control. And even then you are at the mercy of your internet provider even if it is physically your system. My company has quite a few web servers, but since things like AWS came around I don't buy actual hardware any more. AWS is not technically under my control even though I have root access to all the systems that are "mine".

      You're right though. I don't think it would really be an issue, but people have sued over smaller things. The safe way is definitely throw up a copy on your own web server. Knowing it will never be downloaded by anyone just seems to make it such a waste of resources though.

    • A

      Unsolved Is Qt Partner Program available to GPL/LGPL companies?
      Mobile and Embedded • partner gpl technology commercial lgpl • • Ajith_P_V

      5
      0
      Votes
      5
      Posts
      1203
      Views

      SGaist

      @tekojo I knew something wasn't right :D

    • E

      Unsolved Licenças Qt Mobile
      Portuguese • mobile licence lgpl • • Exotic_Devel

      9
      0
      Votes
      9
      Posts
      3639
      Views

      R

      @Exotic_Devel, acredito que não seja culpa do open source, por que:

      Qt usa duas licenças, a Comercial e a LGPL. A licença LGPL diz que:

      o. Em caso de ligação dinâmica, então o teu desenvolvimento (o código que você desenvolver) é "trabalho que usa a biblioteca". Sendo assim, o código que você desenvolver apenas usa as bibliotecas Qt, então seu código pode ser proprietário.

      o. Em caso de vinculação estática da biblioteca, o próprio aplicativo é "trabalho que faz parte da biblioteca". Qualquer ligação estática com uma biblioteca LGPL, obriga a fornecer o código-fonte do aplicativo para o usuário sob a LGPL.

      Então do meu ponto de vista, se existe um culpado, é a Apple! por não permitir vinculação dinâmica! Hora, bastava permitir que resolveria a questão: Quem estivesse sobre licença comercial, faria o vinculo estático; Quem estivesse utilizando alguma biblioteca open, então faria o vinculo dinâmico.

      Não é novidade, isso só reafirma que a Apple não é muito edepta do opensource. :-)

    • M

      Solved Qt 5.5 QWebView Mac LGPL Deployment -- Any Word of Caution?
      General and Desktop • qt5.5 deployment lgpl license qwebview • • maximo

      3
      0
      Votes
      3
      Posts
      1359
      Views

      M

      @SGaist said:

      Where did you got these informations ?

      Nowhere. I just wanted to make certain that this was not true. Your extra information about the Apple Store is very useful -- thanks.

    • B

      Crear un programa propietario y comercial utilizando QT y QML en su versión LGPL
      Spanish • lgpl qml comercial propietario • • bycross028

      1
      0
      Votes
      1
      Posts
      847
      Views

      No one has replied

    • M

      LGPL license and 4 degree of freedom
      General and Desktop • lgpl open source • • maurofaresoftware.it

      9
      0
      Votes
      9
      Posts
      2200
      Views

      A

      Hi @mrjj & @JulienMaille,

      Thanks to both of you for your comments. I was clear on publishing my changes done in Qt sources if working with LGPL license.

      What I misunderstood was the licensing for applications developed using Qt. I was under the impression that an application used for proprietary usage (irrespective of linkage - dynamic or static) requires purchase of license.

      The truth is that if an application is developed using dynamic linkage with Qt libraries, then purchasing of license is not required. Please correct me if I still got it wrong.

      Regards,
      Anant Agrawal

    • M

      Possible To Reverse Engineer My App?
      General and Desktop • reverse enginee dynamic linking lgpl • • maximo

      7
      0
      Votes
      7
      Posts
      3976
      Views

      timday

      There's an interesting post on the Qt Blog which makes a case for how some things about licensed Qt make reverse engineering and hacking more difficult: https://blog.qt.io/blog/2015/02/17/qt-weekly-26-protecting-your-application-against-hacking/ Some of the arguments are more convincing than others.

      I'd be curious to know of any evidence - even anecdotal - of this stuff actually going on. Security and hacking and infosec is a serious business for sure, as is crackability of $100s-$1000s/seat licenses, but for most of us the idea that some team somewhere is waiting to pounce on my FooBar App, rip it's QML and plugins off and put out their own SuperFuBahPlus App is fairly incredible... isn't it????

    • S

      Static and Dynamic linking (LGPL and Commercial)
      Installation and Deployment • lgpl commercial license • • scrolling

      2
      0
      Votes
      2
      Posts
      1779
      Views

      M

      @scrolling said:

      But, what does "dynamic linking" means?

      It applies only to Qt linking. This means that you can use LGPL version for closed source software only if you link dynamically QT libraries