gpl-3.0-exceptions.txt

Linking QCAD libraries statically or dynamically with other modules is making 
a combined work based on the QCAD libraries. Thus, the terms and conditions of 
the GNU General Public License cover the whole combination.

As a special exception, the copyright holders of QCAD give you permission to 
link the QCAD libraries with independent modules to produce an executable or script, 
regardless of the license terms of these independent modules, and to copy and 
distribute the resulting executable or script under terms of your choice, provided 
that you also meet, for each linked independent module, the terms and conditions 
of the license of that module. An independent module is a module which is not 
derived from or based on QCAD. 

If you modify QCAD, you may extend this exception to your version of QCAD, but 
you are not obliged to do so. If you do not wish to do so, delete this exception 
statement from your version.