31.03.2020, 20:34, "Tuukka Turunen" <tuukka.turu...@qt.io>: > Hi Jérôme et al, > > This thread has long ago left the original question and become a discussion > about Qt licensing in general and especially about the point of not mixing > commercial Qt with open-source version of Qt. > > The key point is: The Qt Company, just like Trolltech initially and other > companies in between, does not want mixing open-source Qt and commercial Qt. > > Reason is simple: if mixing was allowed, many companies would use it to pay > less for their use of Qt. > > It is unfortunate that also real open-source projects may be affected in some > cases. Majority of users are not affected in any way. > > It is also unfortunate if licensing is felt to be so complex that it is > better to use some other technology. Commercial licensing of Qt is quite > flexible and it is also possible to negotiate and ask for advice in case it > is unclear what is allowed and what not. > > Here are some examples that hopefully clarify the point about mixing > open-source and commercial: > > Example 1: Company A has 10 developers creating a product. 5 of them use Qt > under commercial license and 5 do not use Qt at all. This is ok. > > Example 2: Company B has 10 developers creating a product. 5 of them use Qt > under open-source license and 5 do not use Qt at all. This is ok. > > Example 3: Company C has 10 developers creating a product. 5 of them use Qt > under commercial license and 5 use Qt under open-source license. This is not > allowed. > > Example 4: Large company D is creating a product with Qt under commercial > license. Part of the work is subcontracted to Company E that uses Qt under > commercial license. This is ok. > > Example 5: Large company F is creating a product with Qt under commercial > license. Part of the work is subcontracted to Company G that uses Qt under > commercial license. Company G subcontracts some of the work further to > low-cost Company H, who uses Qt under open-source license. This is not > allowed. > > Example 6: Company I is building two independent products with separate > development teams. One development team uses Qt under commercial license to > create product 1 and the other development team uses Qt under open-source > license to create product 2. This is ok. > > Hopefully I was able to clarify the topic with these examples. The Qt Company > wants to provide Qt under open-source license. There is no mega corporation > with deep pockets behind. Development of Qt is funded with the revenues > gained from commercial licensing.
Hi, I think this is a kind of explanation which deserves to be in official FAQ. You should also consider adding flowchart or interactive questionary which would show people if their use cases are ok or not after they answer a series of questions about their conditions. Otherwise some people might still end up with impression that licensing terms are unclear (or even intentionally vague). -- Regards, Konstantin _______________________________________________ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
