If a commercial companies to develop commercial software with QT to domestic customers, so need to QT official paid?

Use MFC to develop commercial software piracy, because never want to pay the state of the union,

So using QT does not pay will have what problem? Thank you very much!

CodePudding user response:

Using the LGPL protocol
Qt DLL library cannot encapsulate links must be reflected in the file directory
Documentation may be using Qt

CodePudding user response:

Qt has paid version, there is also a free, open source,

Commercial software developed on the qt open source version, also need not pay,

CodePudding user response:

Use the free version of, literally what software development, only without the technical support of Qt

CodePudding user response:

Suggest you go look at a few agreement, LGPL, GPL, FreeBSD, Apach, etc., in the domestic words generally do not have what problem, domestic environment is inherently more,,, but as far as the international, or the agreement carefully,

CodePudding user response:

About this problem, want to have a basic understanding of open source licenses first
QT open source version of the GPL and LGPL agreement
If you use the open source version of QT, must comply with the open source licenses
About the LGPL with the GPL'd like to know more, see the links below, here I will focus on writing,
http://www.cnblogs.com/findumars/p/3496807.html

Among them, the GPL is strict
In a nutshell, the GPL software user has the authority to get the software code, as long as you use the GPL, at the time of release (" redistribution), the entire project must be of the GPL, namely the main process sequence and the static link library (Linux. A and Windows. Lib) must be of the GPL, dynamic link library (Windows, Linux. So. DLL) must be better than the GPL compatible, the so-called compatible with the GPL, namely the GPL software can be used in the library, the license must be weaker than the GPL (e.g., LGPL, BSD), is not a commercial license, here is a List of compatible with the List of the FSF approved software licenses, and because of this, the GPL is highly contagious, as long as you use the GPL code software, then please open source under the GPL , and also can't have any in your project and the incompatibility of the GPL library,

As long as your software using the GPL code, then please open source under the GPL,
Comb:
If you obey the QT GPL agreement, use the QT library open source, so you should also be open source software, can not commercial,

If you want to use the open source version of QT libraries, also want to use the QT software open source version of the library closed source, commercial,
So you need to know about the LGPL QT,
Want to learn more, the following this blog,
http://www.cnblogs.com/findumars/p/5553490.html

In short
LGPL is one of the GPL is mainly designed for libraries to use open source licenses, and the GPL requires any use/modify/derivatives of GPL software libraries must adopt different under the GPL, LGPL allows commercial software by the class library reference (link) the LGPL library of commercial software without the need for open source code, which makes use of open source LGPL agreement can be commercial software as the class library reference and distribution and sale,

using the LGPL protocol development source program closed, if you use the form of dynamic link, so you can publish your application, in any form of commercial and non-commercial, open source, the open source, with you,


That is to say,

closed source of commercial software can use LGPL free open source version of Qt,

About release:
http://bbs.csdn.net/topics/350224093 please see this post 42 l - 45 l


Is probably the case, according to my check all kinds of information, should be the above conclusion,

CodePudding user response:

Commercial version with pay

CodePudding user response:

When junction post
_ _ (: з ゝ <)

CodePudding user response:

This article is well said: https://blog.csdn.net/aisq2008/article/details/72867134

CodePudding user response:

Learn to understand and pay or not is not the point

CodePudding user response:

The code open source doesn't have to make money!

CodePudding user response:

Here to see so many protocols, meng, completely not heard