[Qt-qml] QML and LGPL?

[Stephen Kelly]

Hi,

The QtScript documentation mentions that use of the module requires LGPL 
compliance because of JavascriptCore:

http://doc.qt.nokia.com/latest/qtscript.html

The QtDeclarative documentation does not mention that, even though it uses 
QtScript and so has the same dependency on JavascriptCore:

http://doc.qt.nokia.com/latest/qtdeclarative.html

That means that anyone distributing a QtDeclarative or QML application needs 
to comply with the licence. That might mean various things such as static 
linking not allowed, must distribute the licence text along with the 
program, must distribute re-linkable files with the program etc depending on 
juristiction, where it gets distributed etc. The licence itself is 
apparently not clear on some of these things:

http://thread.gmane.org/gmane.comp.lib.qt.general/23723/focus=24058

In my experience though, Qt developers think that once they have a Qt 
licence, they can do what they want. So :

1) Should we tell them that use of QtDeclarative might make them need to 
comply with the LGPL (and they have to figure out what that means)
2) Should I file a bug report with Nokia to make that clear in the docs?

The QtScriptClassic module is still available, but I don't know if 
QtDeclarative relies on newer API than that has or JSC quirks. There is also 
work on a V8 backend for QtScript, which is BSD licenced, so it grants a 
different set of rights, but that won't be in Qt before 4.9 at the earliest.

http://labs.qt.nokia.com/2011/02/24/qt-people-our-javascript-platform-is-
burning-rubber/

All the best,

Steve.