My question is interesting. I'm learning QT Framework with C++ but I wonder a topic. I'm writing a project and want to publish it under the GPL license. In this case, do I have to pay a fee for my QT?
Please answer me. Thanks..
I'm writing a project and want to publish it under the GPL license. In this case, do I have to pay a fee for my QT?
No.
Qt is triply-licensed (details) under GPLv2/GPLv3, LGPLv3 (free) and a commercial license (paid); as long as you use the GPL version, you are in the clear even if you distribute your application as a "derived work".
That being said, you can always use the LGPLv3 version of Qt for free in an application with pretty much any other license (including commercial ones) as long as you link dynamically against it or provide the means to the user to re-link your application with his own version of Qt and your application's license doesn't place requirements incompatible with the LGPLv3 (which apparently is the case for GPLv2).
Related
I have a questions with regards to using Webkit as a component in a Windows application. I know there are options for embedding a browser, but they are overkill for my needs.
Looking at the WebKit licensing page, it seems that the licenses are permissible; the traditional BSD license and the Library GPL license, the latter of which allows me to distribute my application as "work that uses the library". This is also stated here. However, I've found several posts (including on Stackoverflow, such as this one) that say that Apple has some proprietary code in there which doesn't allow its redistribution. Is this an inconsistency, or am I missing something?
There are two WebKit Windows ports at the moment:
AppleWin port
WinCairo port
WebKit itself is licensed under LGPL and BSDL.
But, AppleWin port uses Apple's proprietary WebKit Support Library.
This can't be redistributed.
https://developer.apple.com/opensource/internet/webkit_sptlib_agree.html
I am planning to use NvTriStrip library for the software that will be licensed under a commercial license. It is okay to integrate NvTriStrip here?
I could not find a licensing agreement with NvTriStrip,
http://www.nvidia.in/object/nvtristrip_library.html
What is the license of Qt platform (Qt libraries, QT Creator, Designer, Linguist etc) after Digia bought it from Nokia?
Is it still LGPL? Are they planning to enforce their own commercial license? Or will there be three versions of it (GPL/LGPL/Commercial)?
Taken from the Digia's Qt Commercial Blog
Committed to both commercial and open-source licensing
Since we
acquired the commercial licensing business of Qt a bit more than a
year ago the Digia Qt R&D team has been hard at work developing and
releasing not only new and updated features and functions for Qt
Commercial customers, but also working together with the Qt Project
building and releasing both the commercial and LGPL releases,
contributing documentation, bug fixes and improvements mainly to the
desktop and embedded platforms.
...
With this acquisition Digia will have an increasing responsibility to
the global Qt community, not just the commercial licensing business.
We believe in the power of the Qt dual license. It is a great value
for Qt that it can be used under an open source and commercial
license, since customers have different needs and the licenses have
different purposes. Digia wants to continue the good co-operation with
different individual contributors and companies working together in
the Qt Project. We also are committed to continuing the special
relationship Qt has with the KDE community via the KDE Free Qt
Foundation. We believe that this symbiosis is valuable for everyone
involved.
...
We want to work with the entire Qt ecosystem through
the Qt Project to make sure that Qt will continue to thrive both under
commercial and open-source licenses.
Sounds like they want to keep things running the way they are and focus on making the commercial and open source communities even stronger.
I would start using C++ and develop commercials application with GUI. I found Qt libraries and seem that are good for my software.
I saw that Qt has LGPL license, I read that the license allow the developer to create an application and release it with different license, but I don't understand if at the moment I can develop a commercial C++ windows application (closed source) with Qt WITHOUT pay for the Commercial license.
Could someone clarify this point?
Thank you!
The LGPL licence means you can use Qt in a commercial application if, and only if, you dynamically link to it. That means using a DLL (or equivalent for your platform) rather than a static library. As long as you do this you can apply whatever licence you like to your actual application.
Look at the Wikipedia article for more information on the LGPL.
if you do so, you have to provide a way to get the source of the libraries under lgpl you are using.
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I'm looking for free and easy GUI framework that let me create single exe
without dependency (like .Net framework) and to be not GPL
as a side note .. im using Qt and its great but i have to be LGPL to use it that means lots of fat dlls . is there any alternative?
p.s
how did the Dropbox client made of? i know its python but how did they build it? py2exe?
LGPL != GPL. You don't have to make your code LGPL or even make it open to use the library that is covered by this license. It is clarified in this post.
So if LGPL is suitable, then I recommend gtkmm.
AFAIK you can link statically with it.
Another options is wxWidgets which has slightly more liberal license.
As stated here you can create
"an .exe application that will run on any Windows platform with no external dependencies that need to be supplied by the developer" with it.
Also to let you know that from January 14, 2009, Qt version 4.5 is available under LGPL in addition to GPL and commercial license (see here).
What about Win32++?
http://win32-framework.sourceforge.net/index.htm
http://www.codeproject.com/KB/winsdk/framework.aspx
Or WTL?
I found another topic that might interest you
I'm looking for free and easy GUI framework that let me create single exe without dependency (like .Net framework) and to be not GPL
There is no such thing. Three most popular frameworks Qt, GTKmm, wxWidgets are LGPL.
However you can link statically and provide full source code that allows user to replace/update the LGPL part you can do this as it confirms to LGPL requirements
(I'm not a lawyer - don't see this as legal advice).
Now .Net - has lots of dependencies they are just pre-installed.
Now I used to distribute programs with Qt, it was very simple, you need very few dll's. In my case there were: QtCore4.dll, QtGUI4.dll and mingwm10.dll (that is just part of mingw and not Qt). It is not such big problem, so even it is not a single exe but it is simple enough.
Otherwise... Use Win32API -- good luck :-)!
Edit: as it was correctly commented by #vitaut you may even provide compiled objects letting user link the code and replace the Qt version to keep with LGPL requirements.
Or use
http://smartwin.sourceforge.net/
Not specifically C++, but:
AutoIt scripts can be compiled to self-contained executables.
Also consider Free Pascal and the Lazarus IDE which appears to offer the same end-goal.