The license for Geogebra says:

  • You are free to copy, distribute and transmit GeoGebra for non-commercial purposes. Non-commercial use is subject to the terms of our GeoGebra Non-Commercial License Agreement.
  • Any use of GeoGebra for a commercial purpose is subject to and requires a special license. If you intend to use GeoGebra for a commercial purpose, please contact office@geogebra.org to arrange a License and Collaboration Agreement with us.


Non-commercial License Terms


  1. The GeoGebra source code is licensed to you under the terms of the GNU General Public License (version 3 or later) as published by the Free Software Foundation, the current text of which can be found via this link: http://www.gnu.org/licenses/gpl.html("GPL"). Attribution (as required by the GPL) should take the form of (at least) a mention of our name, an appropriate copyright notice and a link to our website located at https://www.geogebra.org.

Aren't these "GPL for non-commercial use only" terms essentially void? If the give me, a non-commercial Geogebra user, a version of their software under GPL3, then I can re-release it under GPL3 to the rest of the world without all other restrictions, making it available under GPL3 for commercial uses as well.


The availability of the source code under the GPLv3 would indeed indicate that commercial use is permitted, but it is under a heading of "non-commercial license terms".

My guess (though truly, the document is unclear enough that it really is just a guess) is that the authors intended to license a subset of GPL rights, i.e., limited to the intersection of what the GPL allows and what constitutes non-commercial use. If so, section 7 of GPLv3 appears to grant the right to eliminate the prohibition on commercial use:

If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term.

I can't say how enforceable this provision is based on the current formulation of Geogebra's terms, but it seems plausible. However, this GPL term is complicated by a statement in Geogebra's terms:

This License incorporates (by reference) additional license terms published by the Free Software Foundation and the Creative Commons Corporation. In the event of any conflict between those additional [GPL] terms and the terms of this License, the latter shall prevail.

So they've selected the GPL, but then said "but when it comes to commercial use, our license prevails in forbidding it" while the GPL itself says, "Restrictive terms additional to this license may be ignored." So both licenses not only disagree with one another, but also have explicit terms saying that their terms take priority over the terms of any supplementary licenses. The Geogebra license is, in a word, a very poorly-crafted legal document.

I don't know how a judge would rule if you decided to use Geogebra's source code under the GPL in a way that contravened Geogebra's non-commercial terms. This might vary by jurisdiction. It's certainly muddy enough that I would not do so unless I was prepared to fight (and expected to win) a legal battle over it.

I will note that the attribution requirement with name and URL might be permitted and could be required on redistribution, as a kind of additional requirement explicitly permitted by Section 7(b), which deals with legal notices.

  • "I don't know how a judge would rule if you decided to use Geogebra's source code under the GPL in a way that contravened Geogebra's non-commercial terms" I agree that that is problematic. If, however, some third-party were to access it under those terms, then simply re-publish under strict GPLv3 (which as you note GPLv3 s7 explicitly permits), the OP could get a copy from them, and neither party has then directly violated Geogebra's terms. – MadHatter Sep 10 '19 at 7:50

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