Can i make freeware(closed source) application using Qt LGPL?

[vangaurd]

Hi...Qt forum,
This is my first post here. My question is quite simple. I want to develop a desktop application with below combination.
1)Developing Qt application using QT sdk (GNU LGPL edition).
2)I want application to be closed source.
3)But it will be available free of charge(Cost free) to end user.
4)Application will be dynamically linked to qt dll(v4.7). And includes Qtcore, Qtgui, Qtxml, QtNetwork, Qtwebkit, Qtsql modules.
5)I will use a open source installer kit(may be nullsoft). Here installer combines qt dlls , and my app's exe to make a setup.exe

Does current qt license(lgpl) provide such feasibility for a developer? I know this question is simple and tricky too. I searched several forums but couldn't find a simple answer like "yes" or "no".
Thanks in advance for replies.

[john_god]

As far as I know, yes.

[squidge]

As long as you dynamically link, yes. You should also state that your application uses Qt under LGPL and state where Qt can be downloaded from (such as in your applications About box)

You can charge for it too if you like.

[SixDegrees]

As long as you dynamically link, yes. You should also state that your application uses Qt under LGPL and state where Qt can be downloaded from (such as in your applications About box)

You can charge for it too if you like.

To be honest, the only advice I would offer would be to contact an attorney for clarification. The latest version of the GPL/LGPL is fantastically complex, and no one really understands its scope yet. There is no doubt that Richard Stallman, et al, would love to expand their influence into dynamically linked executables, and there is reason to believe that the ambiguity of v3 is intentional.

Getting some legal advice from someone with expertise in this area is the only reasonable course to take. Relying on advice rendered through anonymous forums is foolish, and could be quite costly.

[ChrisW67]

The Nokia Qt libraries are licenced under LGPL V2.1, not V3, so the previous comment regarding GPL V3 is irrelevant to the original question.

[vangaurd]

Thank for the replies,
I can understand contacting a legal attorney is always safe. But i cannot effort for a freeware. My intention is to be a part of building strong qt ecosystem by making nice free apps for a common user.
As far as my understanding through the one of the official post at Nokia blog http://blog.qt.nokia.com/2009/11/30/qt-making-the-right-licensing-decision/ the combination i mentioned above seems possible(i am not a lawyer too:) until i dynamically linked to qt libraries & without modifying qt itself(i.e. derived work)..If we derive a class from another class in the LGPL library, that would not constitute a derived work i hope). But i couldn't understood the 4th point under LGPL facts in the above post at Nokia blog regarding including utility tools while shipping application's executable. What i need to include here as a qt application developer.

[squidge]

If you have not modified Qt itself, then including Qt header file for the purpose of inheriting a class is allowed under the permission of including Qt code for its numerical parameters, data structure layouts, accessors, macros, inline functions and templates.

Besides, your app is free. It is marketing Qt for Nokia as an example of its capabilities. They are not going to sue you for breaking a minor rule. The most you'll get is an email or letter asking you to change something. If it was commercial, things would be different (but they'd probably still try to get in to uch with you before trying to sue you, unless you blatently ripped off the library and called it your own or something daft like that)