4 ms·
Exactly. No problem whatsoever selling something made using Qt[0]. But there is a "problem" using Qt to release proprietary software, of course, because Qt is
by hjek 8y ago
Exactly. No problem whatsoever selling something made using Qt[0].
But there is a "problem" using Qt to release proprietary software, of course, because Qt is free, and perhaps parent isn't aware of the distinction between commercial and proprietary?
[0]: https://www.gnu.org/philosophy/selling.html https://www.gnu.org/philosophy/selling.html
- SwellJoe 8y agoLGPL is not GPL. You're adding to the confusion by conflating them.
- munk-a 8y agoThis is incorrect, using LGPL licensed software does not prevent you from keeping your software closed source, any components you rely on from Qt will need to be provided (or reference given which is a _really_ weak requirement) in open source but any functions referencing Qt functions do not themselves need to be provided in a decompiled form, this is pretty much why LGPL exists. So if you're company is trying to make money making proprietary improvements to Qt _which require you to edit Qt_ then you're a bit hooped, but I strongly suspect instead there was a misunderstanding which how contagious free software is. (That said, whenever possible please give back to the FSF community)
- berti 8y agoDoes #including (non-trivial) Qt headers make your software a derivative work? IIRC there is a decent amount of actual code in some of the headers. Seems like a very grey area.
- deleted 8y ago[deleted]
- munk-a 8y agoIt does not, and with significantly complex header files (like the SIGNAL/SLOT macros Qt includes) this can seem like a grey area, but the LGPL specifically splits code into object & specification code, if your code directly references and links against publicly defined specification code you're in the clear... if you are doing this with knowledge of how specific object code works and manipulating that object code using your own code (i.e. intentionally overwriting a stake frame) I think that does become more of a grey area, but the intent of the license is very straightforward about allowing non-contagious use of interface specifications, that is what specifically makes it LGPL instead of GPL (the latter lacks that distinction and does not allow the use you're asking about among some other uses). This is of course complicated by SaaS and all that is covered in more detail in Affero license and in that field I'm out of my depth. Oh also, I am not a lawyer, if you're developing something commercially or otherwise reading this for advice please take a moment to consult a professional.
- berti 8y agoThanks, what you said makes sense, or licensing Qt under LGPL in addition to GPL would make no sense. > Oh also, I am not a lawyer, if you're developing something commercially or otherwise reading this for advice please take a moment to consult a professional. Absolutely!