I noticed the FAQ states the following:
Businesses and government institutions may still use FreeFileSync, but are required to buy the FreeFileSync Business Edition.
While the software is advertised as open source, and provided with a GPLv3 license.In order to allow FreeFileSync in a commercial setting, it is required to license a number of devices for installation by using the form below.
I totally respect your right and ability protect your efforts and sell re-licensed as desired but as far as I can tell (as a non-legal-expert) the above conflicts with the GPLv3.
While the GPLv3 allows the addition of extra terms, they're to the requirements defined in section since otherwise:
I know the following was stated in this thread: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.
But as per section 7 of the GPLv3 license I don't believe this to be true, or at least those additional exceptions/restrictions can be removed and effectively ignored.As the author and copyright owner it is my right to add exceptions to the GPL license as I see fit.
Regardless of specific license, such limitations would go against what most consider the definition of open source (OSD) so preventing specific use, while advertising as open source could be somewhat misleading to many.
Again, I respect the effort that such software must take, and the wonderful fact you are providing that for free, I'm just trying to advise of the potential confusion this could result it by being contradictory.
I think just changing the language around the free edition would help respect the rights of the licensing while putting forward your intent. Something like:
The standard version of FreeFileSync is intended for private use only. The same applies to the FreeFileSync Donation Edition. While the standard version can be used freely under its GPLv3 license, we strongly advise businesses and government institutions buy the very affordable business edition which not only helps sustain this project, but also comes with variety of very useful added features for business.