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What is the licensing story for Qt these days, my understanding is some portions are only available under commercial license or the GPL (vs. others also under t

What is the licensing story for Qt these days, my understanding is some portions are only available under commercial license or the GPL (vs. others also under the LGPL)? https://news.ycombinator.com/item?id=34291701 https://news.ycombinator.com/item?id=34291701

jcelerier 3y ago
Everything you need for a traditional desktop app, or hell, a complete desktop environment, is LGPL. GPL parts are more specialty and industry tools (IoT protocols, etc)
guappa 3y ago
For 20 years people have been commenting that Qt doesn't have LGPL license. This has been false for the past 20 years but people feel the need to write it in a comment any time they read "qt" in a title.
- Capricorn2481 3y ago
  Right, but what the GP wrote was not one of those comments. They are correct. Some parts are LGPL and some aren't.
- saidinesh5 3y ago
  Honestly, Qt company is to blame for this imo. They've relicensed things so many times that you need a complicated chart to figure out the license: https://www.ics.com/sites/default/files/images/licensing.png https://www.ics.com/sites/default/files/images/licensing.png https://i0.wp.com/embeddeduse.com/wp-content/uploads/2023/01/qt6-licensing.png https://i0.wp.com/embeddeduse.com/wp-content/uploads/2023/01... I've lost track of things and I know companies that still stick to Qt 5.6 because of the licensing issues..
  - JanisErdmanis 3y ago
    I didn't know that QtQuick is GPL. That is a commonly used dependency for QML apps. I guess I misread the chart. Can you explain what it means for QtQuick to be purple under the GPL/LGPL section?
    - saidinesh5 3y ago
      That's the QtQuick 2D renderer. They mostly use that on devices without a decent 3D GPU. That was also Qt 5.7. With Qt 6, QtQuick itself is part of QtGui now. It is available under LGPLv3 and additionally under GPLv2, GPLv3, Qt for Device Creation Professional (Pro) and Qt for Device Creation Enterprise (Enterprise). But the embedded companies I've worked with tend to avoid LGPLv3 because of the anti tivoisation clause. (To let the end users swap out the Qt libraries on your devices).

jcelerier 3y ago

Everything you need for a traditional desktop app, or hell, a complete desktop environment, is LGPL. GPL parts are more specialty and industry tools (IoT protocols, etc)

guappa 3y ago

For 20 years people have been commenting that Qt doesn't have LGPL license. This has been false for the past 20 years but people feel the need to write it in a comment any time they read "qt" in a title.

Capricorn2481 3y ago
Right, but what the GP wrote was not one of those comments. They are correct. Some parts are LGPL and some aren't.
saidinesh5 3y ago
Honestly, Qt company is to blame for this imo. They've relicensed things so many times that you need a complicated chart to figure out the license: https://www.ics.com/sites/default/files/images/licensing.png https://www.ics.com/sites/default/files/images/licensing.png https://i0.wp.com/embeddeduse.com/wp-content/uploads/2023/01/qt6-licensing.png https://i0.wp.com/embeddeduse.com/wp-content/uploads/2023/01... I've lost track of things and I know companies that still stick to Qt 5.6 because of the licensing issues..
- JanisErdmanis 3y ago
  I didn't know that QtQuick is GPL. That is a commonly used dependency for QML apps. I guess I misread the chart. Can you explain what it means for QtQuick to be purple under the GPL/LGPL section?
  - saidinesh5 3y ago
    That's the QtQuick 2D renderer. They mostly use that on devices without a decent 3D GPU. That was also Qt 5.7. With Qt 6, QtQuick itself is part of QtGui now. It is available under LGPLv3 and additionally under GPLv2, GPLv3, Qt for Device Creation Professional (Pro) and Qt for Device Creation Enterprise (Enterprise). But the embedded companies I've worked with tend to avoid LGPLv3 because of the anti tivoisation clause. (To let the end users swap out the Qt libraries on your devices).