May one create an open source scripting application using QtScript?

Question

Hi there,

I'd like to implement my own script engine using the QtScript component and other Qt components. Since this should be an open source (GPL) application I thought I would be free to do this.

But now I found a page at Qt's website that made me doubtful about it:

What are the restrictions with releasing scriptable applications?

Unless the scripter has a Qt license, the following restrictions apply:

• The application itself may not primarily be a script development tool.
• The Qt API may not be made directly scriptable.
• Scripts may not alter the main functionality of the application.

If the major part of the application is developed with a compiled programming language and only some non-core parts of the application are made extendable/modifiable through Qt Script, the scripter does not need to purchase a Qt or QSA license.

Does this text apply to my project or not?

Cheers,

Manuel

Answer 1

Looks like it applies, unless you have a Qt license.

Answer 2

But isn't Qt {GPL|LGPL}ed? So why can its use be restricted?

Answer 3

Qt's FAQ is really bad written and confusing (unlike the rest of their website)...

If you go back one level, from the web page you are referring to, you will see that the previous questions refer to using QSA within a commercial application.

You don't need to buy a license if you are using QSA Open Source Edition, as long as your application is under the GPL.