Hello,
I've developed an application using the LGPL version of Qt. I've went over the LGPL license (http://www.gnu.org/licenses/lgpl-2.1.html), but am looking for a little clarification on some things.
I've used the Qt library without any modification, and the executable that will be shipped will be built with mingw on Windows. The application will be dynamically linked to the Qt library, and also dynamically linked to any other libraries from mingw. The source code of the application is proprietary.
Firstly, based upon the license information found on the mingw site (http://www.mingw.org/wiki/FAQ), it's my understanding that the DLLs
- libgcc_s_dw2-1.dll
- mingwm10.dll
fall under public domain. Is this correct? Or does libgcc_s_dw2-1.dll not fall under the definition of the "MinGW runtime"?
Concerning Qt and the LGPL license, as I have not modified any part of the library, I believe section 6 applies.
Section 6 says:
My application would be a "work that uses the Library", thus I can distribute only the executable to my application, and not the source code. Correct? And it's my understanding that the last part, says that whatever terms I release my application under, I cannot expressly forbid reverse engineering it? Is this Correct?As an exception to the Sections above, you may also combine or link a "work that uses the Library" with the Library to produce a work containing portions of the Library, and distribute that work under terms of your choice, provided that the terms permit modification of the work for the customer's own use and reverse engineering for debugging such modifications.
Now, when I ship my application, I would need to include the mingw related DLLs as described above, and also:
- QtCore4.dll
- QtGui4.dll
My understanding of the license is that I can freely distribute these DLLs, and only need to provide a copy of the LGPL license and a location (i.e., qt.nokia.com) to download the source code of the library from. Is this Correct?
tl;dr I am releasing an application which uses the LGPL version of Qt. Can I keep my application's source code proprietary, and freely distribute the Qt shared libraries (DLLs)? And, what other obligations do I have to the terms of the LGPL?
Thank you if you've read this far, this is my first commercial work, and I am a little paranoid about my obligations to licensing issues. I appreciate any answers to the questions above.
Thank you.
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