The same old topic: Licensing.
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Hi,
I need to prepare a lecture for my colleagues about Qt Development, and one of the topics is licensing. But it's a very controversial topic, since the three Qt licenses make its licensing hard to understand. I tried to read "Qt Licensing(Qt Licensing)":http://qt.nokia.com/products/licensing) a few times, but I'm still confused.
So, I'll start with a some questions:
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Can I develop and deploy closed-sourced commercial applications without buying a commercial license of Qt?
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A more specific question, since the answer may be different: can I develop and deploy closed-sourced commercial applications without buying a commercial license of Qt, distributing it with the original Qt libraries, without any changes on it?
My personal projects are free and open sourced, but I need these questions answered so I could convince (or not...) some coworkers to use Qt on their commercial projects.
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IANAL, but in my understanding: Yes & yes. You need to comply with the LGPL 2.1 though.
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To my understanding you must also make the source code available.
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[quote author="ucomesdag" date="1275403434"]To my understanding you must also make the source code available.[/quote]
Which source code?
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Not a lawyer too, but AFAIK you can distribute your closed-source commercial software with or without original Qt libraries if you use LGPL. And you con't need to provide source code by this license.
AFAIR there are some issues with static linking with Qt libraries.
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You do not need to distribute the application source code (ref. LGPL section 6) as long as the application is only dynamically linked to Qt (which is the ordinary case). Then the LGPL allows you to distribute your application under "the terms of your choice" (i.e. any license you like), provided that those terms "permit modification of the work [i.e., your application] for the customer's on use and reverse engineering for debugging such modifications."
If you modify Qt itself, then you must distribute the source code of your modified version of Qt if you want to distribute an application that uses it. You still do not have to distribute the source code of your application.
(Standard disclaimer: this is not official Nokia legal advice blah blah blah)
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[quote author="aavit" date="1275465885"]"permit modification of the work [i.e., your application] for the customer's on use and reverse engineering for debugging such modifications."[/quote]
To what extent is this required, do you just not sue them when they hack your app, or provide the ability to write plugins, or prpovide debug libraries (basically as good as source code, isn't it?)
This is very interesting, I love Qt personally... But I always thought the licencing thing would stop me producing closed source apps or commercial programs...
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[quote author="jorjpimm" date="1275466723"] To what extent is this required, do you just not sue them when they hack your app, or provide the ability to write plugins, or prpovide debug libraries (basically as good as source code, isn't it?)[/quote]
As I read it, the LGPL in this regard only places restrictions on the terms of the (optionally commercial, closed-source) license that you choose to distribute your application under. In effect, the LGPL says that that license may not contain things like "modifications or reverse-engineering is not allowed".
The FSF may provide more in-depth on this: http://www.fsf.org/licensing/
[quote author="jorjpimm" date="1275466723"] This is very interesting, I love Qt personally... But I always thought the licencing thing would stop me producing closed source apps or commercial programs...[/quote]
While that might have been an issue earlier, while Qt was under Trolltech's business model, it should not be now, after Nokia started releasing Qt under LGPL also (which happened about a year ago).
(Standard disclaimer applies)
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more open than i thought! Cool, however open source will still remain my distribution of choice i think.
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Have a look at this blog post for information about this directly from Qt legal:
"http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/(http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/)":http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/
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[quote author="MariusG" date="1275501216"]Have a look at this blog post for information about this directly from Qt legal:
"http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/(http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/)":http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/
[/quote]Has that page changed recently? Because I'm sure I have been on a page with the same title, and it used to be not so useful, but now looks very good.
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Apart from a small css update it's the same as before.
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[quote author="MariusG" date="1275501216"]Have a look at this blog post for information about this directly from Qt legal:
"http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/(http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/)":http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/
[/quote]Thanks that made it all clear to me!
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Since comments at
http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/
are closed, I was wondering if I could have an answer at the following scenario/question:
If someone writes a closed-source Qt application for Windows based on the LGPL-licenced Qt framework, and if he/she doesn't change the libraries, and if he/she linked dynamically with the dlls (Qt for Windows) then:
a) if he/she doesn't provide the dlls but he/she only provides the exe
b) if he/she provides both the exe and the dllsdoes he/she has to provide the (unchanged) source code of the dlls?
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Stavros Filippidis, AFAIK in both cases you shouldn't provide code.
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@Denis Kormalev: Just to clarify, I am NOT referring to the source code of the application, but to the source code of the Qt libraries (QtCore4.dll, QtGui4.dll, etc). In any case, I am not a lawyer, I am just have these questioned unanswered. :)
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[quote author="Stavros Filippidis" date="1276707919"]@Denis Kormalev: Just to clarify, I am NOT referring to the source code of the application, but to the source code of the Qt libraries (QtCore4.dll, QtGui4.dll, etc). In any case, I am not a lawyer, I am just have these questioned unanswered. :)[/quote]
Yeah, I understood that question is about Qt sources. Anyway when you use Qt with LGPL license you need to provide link to Qt. And everybody who wants can take sources from Qt website.
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(oooh, second page, ive never seen that before, very cool)
I think Qt could do more to explain its licences simply, as the previously linked page tried to do... I think there could be a further simplification of it...
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We agree. However, licensing (and law in general) unfortunately isn't easy to simplify while giving correct information...
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@Alexandra: In my opinion, it would be interesting if you would consider re-opening comments at
http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/
so that someone from Qt/Nokia's legal department could clarify additional questions that we could post there. ;)
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Stavros Filippidis, good idea. Also may be good will be to make FAQ about licensing issues. Alexandra Leisse, what do you (and other Trolls) think about it?
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[quote author="Alexandra Leisse" date="1276777620"]We agree. However, licensing (and law in general) unfortunately isn't easy to simplify while giving correct information...[/quote]
What about some simple use cases, specifying when and why you should use each licence... Although I suppose if it was that simple it would already exist...
A tricky topic....
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I just talked to our lawyer and she has already planned for a follow-up to mentioned "blog(Licensing blog)":http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/. To make it easier for her to figure out what is still unclear and would be good to address, I have started "a wiki page(Licensing wiki)":http://developer.qt.nokia.com/wiki/LicensingQuestions.
Please, add your questions/suggestions there and we do our best to provide you with answers.
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[quote author="Alexandra Leisse" date="1276877146"]I just talked to our lawyer and she has already planned for a follow-up to mentioned "blog(Licensing blog)":http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/. To make it easier for her to figure out what is still unclear and would be good to address, I have started "a wiki page(Licensing wiki)":http://developer.qt.nokia.com/wiki/LicensingQuestions.
Please, add your questions/suggestions there and we do our best to provide you with answers.[/quote]
I have just created this:
http://developer.qt.nokia.com/wiki/Question_Closed-source_application_scenario
But maybe I did something wrong and I do not see it at the Wiki! Could a TROLL please correct this? :)
EDIT:
I just noticed that I was supposed to EDIT the
http://developer.qt.nokia.com/wiki/LicensingQuestions
and NOT create a new wiki-page! So ... now I dit it (correctly!)!
Could a TROLL (please!) delete the
http://developer.qt.nokia.com/wiki/Question_Closed-source_application_scenario
which I shouln't have created the first place?
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[quote author="Stavros Filippidis" date="1277156563"]
Could a TROLL (please!) delete the
http://developer.qt.nokia.com/wiki/Question_Closed-source_application_scenario
which I shouln't have created the first place?
[/quote]Done. Thanks for adding this scenario!
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Yes, that scenario seems to cover the area in the middle I am more confused on... Interesting to see the result - thanks Stavros.
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When are the answers on the referenced wiki page going to be answered, or have they already and I'm just not finding them?
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[quote author="jeremy_c" date="1282830434"]When are the answers on the referenced wiki page going to be answered, or have they already and I'm just not finding them?[/quote]
Currently, Cristy - our lawyer - is working on her presentation for our Developer Days. The wiki is basis for that, among other things. It's supposed to help her understand what our users a struggling with.
After the event in San Francisco we will make her presentation available publicly.
I hope that helps.
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[quote author="Alexandra Leisse" date="1283252630"][quote author="jeremy_c" date="1282830434"]When are the answers on the referenced wiki page going to be answered, or have they already and I'm just not finding them?[/quote]
Currently, Cristy - our lawyer - is working on her presentation for our Developer Days. The wiki is basis for that, among other things. It's supposed to help her understand what our users a struggling with.
After the event in San Francisco we will make her presentation available publicly.
I hope that helps.[/quote]
Do we have anything new on the licencing follow-up with Cristy? :)
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[quote author="Stavros Filippidis" date="1293545620"]Do we have anything new on the licencing follow-up with Cristy? :)[/quote]
The video is available "here":http://qt.nokia.com/developer/learning/online/talks/developerdays2010/qt-in-use
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[quote author="Esdras Beleza" date="1275400201"]Hi,
I need to prepare a lecture for my colleagues about Qt Development, and one of the topics is licensing. But it's a very controversial topic, since the three Qt licenses make its licensing hard to understand. I tried to read "Qt Licensing(Qt Licensing)":http://qt.nokia.com/products/licensing) a few times, but I'm still confused.
So, I'll start with a some questions:
-
Can I develop and deploy closed-sourced commercial applications without buying a commercial license of Qt?
-
A more specific question, since the answer may be different: can I develop and deploy closed-sourced commercial applications without buying a commercial license of Qt, distributing it with the original Qt libraries, without any changes on it?
My personal projects are free and open sourced, but I need these questions answered so I could convince (or not...) some coworkers to use Qt on their commercial projects.[/quote]
If you are preparing lecture and need the material regarding it then "Qt in Education":http://qt.nokia.com/services-partners/qt-in-education will help you.
Check this "presentation":http://www.slideshare.net/qtbynokia/presentations also.
About licensing ,I think LGPL will not make any problem for you, As obvious you can not distribute that one.
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LGPL libs can be distributed. As long as you use dynamic libs and you do not modify the Qt libs you are on the safe side.
And please: No speculations on licensing topics ("I think..."). It is too delicate and does more harm than help.
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[quote author="Volker" date="1293547101"][quote author="Stavros Filippidis" date="1293545620"]Do we have anything new on the licencing follow-up with Cristy? :)[/quote]
The video is available "here":http://qt.nokia.com/developer/learning/online/talks/developerdays2010/qt-in-use[/quote]
Thanks for the link! Very interesting video and quite enlightening. Unfortunately, I did not get the answers I was looking for the two first questions in
http://developer.qt.nokia.com/wiki/LicensingQuestions
Maybe the comments at
http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/
should open again? ;)
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I will remind her of the wiki again. Maybe we can get some answers based on the questions directly. No promises though, she's doing all she can.
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[quote author="Alexandra Leisse" date="1294056575"]I will remind her of the wiki again. Maybe we can get some answers based on the questions directly. No promises though, she's doing all she can.[/quote]
Thanks in advance Alexandra! I think that the answers two these questions are very important for non-legal-expert-qt-developers, so we will be looking forward for answers.
By the way, IMHO, Cristy is doing a great job! The video http://qt.nokia.com/developer/learning/online/talks/developerdays2010/qt-in-use/breakfast-seminar-qt-licensing-explained was very insightful. :)
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I don’t want to open new topic, and I don’t know if these are told somewhere else, so...
What about licences of Qt related stuff but not in the repository by Nokia? This particular case I have is related to Qt logo(not actually stealing image from Qt site but just using the logo), but maybe there is others, maybe mainly art in the sites.
Sorry if I’m asking something too obvious... Like, the logo is available in git repo? :)
That leads me to another question: can I count on that everything in the Qt repos are licenced under LGPL/GPL?
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For the logo: Guidelines are on the "logo download":http://qt.nokia.com/about/logos-for-download/ page
For the files in the repos: They should have a license statement on the top (some of them are from other sources and may have another license!)
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[quote author="Volker" date="1294233087"]For the logo: Guidelines are on the "logo download":http://qt.nokia.com/about/logos-for-download/ page
For the files in the repos: They should have a license statement on the top (some of them are from other sources and may have another license!)[/quote]
Pictures and format restricted files can’t really have the licence, though... Maybe in meta tag, but those are cumbersome to look at, if they even exist.
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They may have a README in the directory they live on... Hard to say, some of the Troll's license specialists should better comment on this. Maybe it's better to start a new thread for this, so that it gets some attention.
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[quote author="Alexandra" date="1294056575"]I will remind her of the wiki again. Maybe we can get some answers based on the questions directly. No promises though, she's doing all she can.[/quote]
Anything new on this? :-)
