We license the different component parts of GeoGebra differently depending on their origin (authorship) and depending on your intended use of GeoGebra (see also next question)
- the source code is licensed under the GNU General Public License to ensure consistency with the various other pieces of software and libraries which are used within the GeoGebra source code (for a complete list of which see: https://wiki.geogebra.org/en/Reference:Sources_For_Used_Libr...).
- the GeoGebra installers (for various platforms including Linux, Mac OS, Windows, Android, iOS) and our web services (including GeoGebra Materials platform) are made available under our own licensing terms which have been drafted by an experienced law firm. We allow you to use the installers and web services for non-commercial purposes only provided you acknowledge GeoGebra; and
- the GeoGebra language files are made available under a Creative Commons license, which allows non-commercial use of these files.
Thus, there are really many different licenses involved in the background.”
I also noticed that one of their non-free options allows you the use of their logo. IANAL, but I don’t think the GPL automatically allows you that.
Also, the engine is GPL-licensed, but the installer isn’t. https://www.geogebra.org/license#FAQ:
“How is GeoGebra licensed?
We license the different component parts of GeoGebra differently depending on their origin (authorship) and depending on your intended use of GeoGebra (see also next question)
- the source code is licensed under the GNU General Public License to ensure consistency with the various other pieces of software and libraries which are used within the GeoGebra source code (for a complete list of which see: https://wiki.geogebra.org/en/Reference:Sources_For_Used_Libr...).
- the GeoGebra installers (for various platforms including Linux, Mac OS, Windows, Android, iOS) and our web services (including GeoGebra Materials platform) are made available under our own licensing terms which have been drafted by an experienced law firm. We allow you to use the installers and web services for non-commercial purposes only provided you acknowledge GeoGebra; and
- the GeoGebra language files are made available under a Creative Commons license, which allows non-commercial use of these files.
Thus, there are really many different licenses involved in the background.”
I also noticed that one of their non-free options allows you the use of their logo. IANAL, but I don’t think the GPL automatically allows you that.