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LibqtXpas LGPL license
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LeP:
--- Quote from: PascalDragon on June 30, 2026, 11:14:13 pm ---
--- Quote from: robert rozee on June 30, 2026, 02:57:27 pm ---being able to produce a fully self-contained ELF binary suddenly makes Qt far more attractive for users of Lazarus/FPC.
--- End quote ---
Only for users that create open source code, because due to libqtXpas being licensed as LGPL, this prohibits its use with a proprietary, closed source application (at least if you want to distribute it as a precompiled binary).
--- End quote ---
(I created a new topic from that, since what I write now is OT: https://forum.lazarus.freepascal.org/index.php/topic,74288.msg585654.html#msg585654 )
I'm confused, why you said that ?
The LGPL license allows the use of the library in any form (open source, closed source, etc.), provided that any modifications are made public.
Is my understanding correct, or am I completely wrong?
zeljko:
Yes, you can use it with LGPL as you mentioned, BUT you cannot deploy static builds without commercial license.
LeP:
@zeljko, thanks.
That is, if I have a component/library or something else licensed under the LPGL (standard), I can't build an EXE (I'm talking about Windows) that already contains the library code.
Should I use it as a separate module, like a DLL or something else?
To use it and build a monolithic EXE, do I need to, as you mentioned, obtain a commercial license for the "component," or use a "component" like those licensed by FPC with "Modified LGPL with linking exception," for example?
Thaddy:
As long as it is a monolitic executable as result, that does not matter...
If the monolith contains Qt itself, statically linked, - in any way - a commercial license is required for its distribution if not all of the sourcecode is publicly available.
lgpl does not matter in that case.
IOW if you distribute a component with full sourcecode that component can be lgpl'd, but when the user of that component creates a monolithic application with it, it is that user's responsibility to buy a commercial license from Qt if so required: if he does not distribute or makes publicly available all sources with all applicable open source licenses.
LeP:
Thanks @Thaddy for the reply.
My question wasn't meant to be specific to QT (I took inspiration from the reference discussion) but rather to be about the LGPL and its possible variants, and QT worked well as an example.
All this as a reflection on the new regulations and how to deal with components like those, where the license forces you to have an external component, effectively uncontrolled because it's not digitally signed (unless you sign it yourself), and since it's open-source and free, no one (except those who use it) responds.
The LGPL license also allows for the possible replacement and updating of the component, as well as its debugging... and I'm getting a general overview of what this entails in general with the new regulations (CRA in particular).
I struggle to imagine the SBOM being "glued" to components of this type.
But we'll see.
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