[PyQt] Scripting framework and licensing

Ulrich Berning ulrich.berning at denviso.de
Thu Feb 19 10:55:59 GMT 2009

Simon Hibbs wrote:

> I understand that user-written Python scripts in a commercial PyQT 
> application isn't allowable as it makes them effectively developers. 
> That's a pity but completely understandable.
> However does this also apply to using the QT scripting framework? It 
> would be useful to enable users to write their own algorithms for some 
> calculations in an application I'm working on, and Javascript would do 
> the job just fine.

 From paragraph 11 of the Qt commercial license agreement version 3.5 

(vii) Applications may not pass on functionality which in any way makes
it possible for others to create software with the Licensed Software,
however Licensee may use the Licensed Software's scripting functionality
solely in order to enable scripting that augments the functionality of
the Application(s) without adding primary and substantial functionality
to the Application(s);

IMHO this means:

1.) You have to ensure that nobody can use PyQt independent of your 
application. Take a look at the VendorID package on 
www.riverbankcomputing.com. Just installing Python/Qt/PyQt and your 
application script(s) on a target machine violates the Qt commercial 
2.) It is allowed to use the Qt scripting framework in your application, 
but it is not allowed to use any other scripting framework (e.g. 

When Qt 4.5 will be released under the LGPL, it should be allowed to use 
Python/PyQt as a scripting framework inside an application. If it will 
be allowed to install PyQt on target machines without any restictions 
depends on PyQt's license.


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