How can Lumnia be licensed under the BSD-3 when it uses qt5?


#1

I looked over the Lumina code on github and saw that it is licensed under the BSD-3 license. I’m not sure how this can be because some of Lumina’s code seems to be from qt5.

So in order to edit Lumina, wounldn’t the user have to download qt creator and accept their (Qt’s) license agreement??


#2

One can write code to use QT without using qt creator. It’s just a matter of including the correct headers and linking against the right libraries. It also looks like QT is available LGPL.


#3

It also looks like QT is available LGPL.

Yes, it is, as stated in https://www1.qt.io/qt-licensing-terms/.

In case of dynamic linking, it is possible, but not mandatory, to keep application source code proprietary as long as it is “work that uses the library” – typically achieved via dynamic linking of the library. In case of static linking of the library, the application itself may no longer be “work that uses the library” and thus become subject to LGPL. It is recommended to either link dynamically, or provide the application source code to the user under LGPL.

As long as the library is dynamically linked to the appliction (parts of Lumina) and the source code of the library is provided, there should be no problem.

Complete corresponding source code of the library used with the application or the device built using LGPL, including all modifications to the library, should be delivered with the application (or alternatively provide a written offer with instructions on how to get the source code). It should be noted that the complete corresponding source code has to be delivered even if the library has not been modified at all.

The code can even be created/changed using Qt Creator without any hassle.


#4

Thanks for providing details. I hate trying to explain licensing terms to people because there is the legal view (the licenses create legal obligations) and then there is the practical view (what does this mean to the code I’m writing). The two views should be the same be often are difficult to state.