Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. Why Qt has 3 Licenses?

Why Qt has 3 Licenses?

Scheduled Pinned Locked Moved General and Desktop
4 Posts 4 Posters 1.2k Views 1 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.
  • CAD_codingC Offline
    CAD_codingC Offline
    CAD_coding
    wrote on last edited by
    #1

    Hi,

    I am creating my application using Qt for a while & I am nearing its completion. I want to make it open source, but also have commercial interest in it due to the hard work, time, etc put up by me in it. So I find it apt to release my application under 2 licenses - LGPL & Commercial.

    But then I realise Qt is additionally licensed for GPL also. I am unable to understand why is this done?
    Suggestions, Personal opinions are strongly welcome!
    Thanks!

    1 Reply Last reply
    0
    • S Offline
      S Offline
      Serenity
      wrote on last edited by
      #2

      The GPL and commercial licenses were first, the LGPL license came later.
      Why the GPL still exists, I don't know. It's maybe a rudiment of Qt. It could be also an agrement with the KDE.

      You should know, if Qt. didn't get updates during a special periodic, the project will be licensed under BSD (see wikipedia: . This led to the creation of the KDE Free Qt foundation, which guarantees that Qt would fall under a BSD-style license should no free/open source version of Qt be released during 12 months. )

      1 Reply Last reply
      0
      • francescmmF Offline
        francescmmF Offline
        francescmm
        wrote on last edited by
        #3

        I'm not a license expert, but I remember that I read in some place that a condition to sell Qt by Trolltech to Nokia was that the code must continue with the GNL open source license.

        1 Reply Last reply
        0
        • K Offline
          K Offline
          koahnig
          wrote on last edited by
          #4

          On KDE you find the "KDE free Qt foundation terms":http://www.kde.org/community/whatiskde/kdefreeqtfoundation.php and in there :
          [quote]
          The Foundation has a license agreement with Digia and Nokia. This agreement ensures that the Qt will continue to be available under both the LGPL 2.1 and the GPL 3. Should Digia discontinue the development of the Qt Free Edition under these licenses, then the Foundation has the right to release Qt under a BSD-style license or under other open source licenses. The agreement stays valid in case of a buy-out, a merger or bankruptcy.
          [/quote]

          Vote the answer(s) that helped you to solve your issue(s)

          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