I received a response from FSF by Yoni Rabkin, a volunteer with FSF. I asked permission to post his reply here so we can further discuss this here. The first mail is my initial mail to FSF. After the ==================== you can read the response by Yoni:
Hi to all at fsf,
I am writing this mail because I asked in the #fsf IRC channel on freenode.net how we (NethServer project) should handle possible license incompatibilities.
NethServer is a modular Linux distribution that builds on top of a CentOS minimal install. There is a ISO which ships CentOS + the base modules of NethServer as an installer.
To enhance the base install there are several modules available through official NethServer repository and NethForge community repository.
Besides the official repositories, there are some repositories however maintained by NethServer community members, that are not part of the official repositories.
As a community we encourage our members to develop new modules so the functionality of NethServer is extended even further. Most of these modules that are developed are existing applications that are (re)packaged so they seamlessly integrate with NethServer and the NethServer webinterface.
If I look at https://en.wikipedia.org/wiki/Comparison_of_free_and_open-source_software_licenses#Approvals I see a lot of licenses that are incompatible with GPLv3.
My questions would be:
What if someone wants to add a module to NethServer and the application that he or she wants to add as a module is licenced under a license that is not compatible with GPLv3, what options do we have to be able to make that module available?
In what way should the NethServer project and community act to respect the licenseforms without limiting the options of adding extra functionality? Is that possible?
Would it be considered 'good practice' if an application that is not compatible with GPL v3, is offered through a repository that is not linked with the NethServer project?
A specific example could be: an application that uses php, can that be shipped with NethServer? (GPLv3 and PHP license are not compatible)
Can you give me some insight in this matter and/or point me to documentation that explains this matter?
best regards and merry x-mas to you all!
NethServer community team member
Hello and thank you for writing in.
Hi to all at fsf,
I am writing this mail because I asked in the #fsf IRC channel on
freenode.net how we (NethServer project) should handle possible
I was the one who suggested you do so. My name is Yoni Rabkin and I am
one of the volunteers who helps answer licensing questions at this
I saw your email come in and decided to start the conversation right
NethServer is a modular Linux distribution that builds on top of a
CentOS minimal install. There is a ISO which ships CentOS + the base
modules of NethServer as an installer.
The Nethserver site states that "the whole project" is under GPLv3. I
understand that to mean that original code by the project developers is
licensed under GPLv3. But note that a complete GNU/Linux distribution is
not licensed, as a whole, under a single license. A GNU/Linux
distribution is typically a collection of many thousands of individual
programs, each with their own copyright holder/s and license. While the
GPL is a very popular license, a typical GNU/Linux distribution will
contain software under many other licenses, and not all of them are GPL
Just for instance: the kernel Linux is distributed under GPLv2
only. Because each version of the GPL is a strong copyright GPLv2 and
GPLv3 are mutually incompatible.
However this incompatibility need not be a problem. Most of the software
distributed as a part of a GNU/Linux distribution is in what we call
"mere aggregation". See:
In the case of the kernel Linux above, this means that the license would
only be a problem if you included GPLv2-incompatible code as part of the
kernel Linux itself, as opposed to software in userland which merely
uses the kernel.
In the case of PHP, Wordpress is a famous example of software written in
PHP which is released under the terms of the GPL. This is possible
because the license of the PHP4 implementation (PHP License, Version
3.01) normally doesn't cover software written in the language. If you
were by contrast modifying the PHP4 engine itself or its libraries you
would not be able to license those modifications under the GPL.
Finally, if someone were to modify your own original GPLv3-licensed
code, they could only do so if they released their work under GPLv3 as
* A GNU/Linux distribution need not necessarily contain only
mutually compatible free software licenses.
* Free software license compatibility is important when you are
modifying, or linking together, pieces of software in a way which
would otherwise require permission from the copyright holder.
I hope this is of help. Please feel free to write back with further
questions if needed.
I am not a lawyer, the above is not legal advice
Regards, Yoni Rabkin
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