Nexedi stack is licensed under Free Software licenses with various exceptions that cover three business cases: Free Software, proprietary software and rebranding. As long as one intends to develop Free Software based on Nexedi stack, no license cost is involved. Developing proprietary software based on Nexedi stack may require a proprierary exception license. Rebranding Nexedi stack is prohibited unless rebranding license is acquired.
Through this licensing approach, Nexedi expects to encourage Free Software development without restrictions and at the same time create a framework for proprietary software to contribute to the long term sustainability of Nexedi stack.
Nexedi stack is published by default as Free Software under GPLv3 license with a wide Free Software exception that ensures compatibility with all other Free Software licenses. Nexedi stack can thus benefit from the largest portfolio of Free Software which is dominated by GPL license families.
Nexedi supports the Free Software Foundation's effort to create a solid copyleft license that protects long term innovation and users's freedom.
Through a wide Free Software exception, developers are free to select whichever Open Source / Free Software license they prefer for their original work based on Nexedi stack. Yet, they must adhere to GPLv3 for mere improvement of Nexedi stack. In other words, By chosing GPLv3 license with wide exception.
GPLv3 license may be unsuitable for developers of proprietary software. Nexedi thus provides a Proprietary Software exception that is compatible with original proprietary software based on Nexedi stack. The cost of this license is 100€ per year. Under this license, developers are required to contribute to Nexedi stack either in reputation through links to Nexedi stack or in cash through R&D sponsorship.
Contribution in reputation is ideal for companies willing to save cash. Contribution in R&D sponsorship is ideal for profitable companies that eventually benefit from tax exemptions. It is of course possible to combine both.
Companies willing to rebrand Nexedi stack must acquire a rebranding license for Nexedi stack. Cost depends on each case and is significantly higher than exception for proprietary software. Rebranding license includes accessunder MIT license to the code base of Nexedi stack and access to other intangible assets such as trademarks that are required for rebranding.
Nexedi stack licensing options are summarised belllow.
Why should I care about Nexedi stack when Google or Facebook provide so many good libraries with no copyleft?
Because Nexedi stack is better designed for Enterprise software and is maintained and will be maintained with vitually no requirement to change code during 10 years or more.
Why did you chose GPLv3 rather than LGPLv3, BSD, MIT, MPL, etc.?
Because we want to provide the highest degree of flexibility to Free Software developers in terms of ability to reuse other Free Software and because the majority of Free Software is licensed under GPL type licenses. Thanks to GPLv3 license, we ensure that about any Free Software can be combined with Nexedi stack without having to ask a Lawyer or request permission from the author.
Why did you chose GPLv3 rather than AGPLv3?
Because we believe that GPL type licenses already provide a good balance between rights and obligations. Also, GPL type licenses have proven their ability to support businesses with many successful software such as Linux kernel or MariaDB database.
Why did you chose GPLv3 rather than GPLv2?
Because GPLv3 is better written than GPLv2 from a continental Law perpective. However, we are open to discussion on this topic in order to improve future versions of GPLv3.
Why did you add an exception for Free Software?
Because we want to be sure that any Free Software can be combined with Nexedi stack, including software based on Free Software licenses that are incompatible with GPLv3 license without explicit exception. Generally speaking, we want to provide the highest degree of flexibility to Free Software developers in terms of choice of license for their own code.
Why didn't you add an exception for proprietary software or chose LGPLv3 license?
Because we want to ensure that proprietary software developers contribute to Free Software.
Why do you want proprietary software developers to contribute to Free Software?
Because we believe that it is unfair that proprietary software developers retain all profits for themselves. We do understand though that that our belief may not be shared by everyone.
Why do you ask proprietary software developers to pay 100€ per year for a license exception?
Because this is the price of a good lunch for two people in Paris, Tokyo, Munich or Shanghai and we think that anyone seriously willing to base their proprietary software business on Nexedi stack can spend such an amount. Needless to say, if you visit one of our offices, we'll be glad to share this lunch with you.
Why don't you let proprietary software developers freely contribute to Free Software?
Because the freedom not to contribute ends up too often with no contribution at all, even for companies with billions of dollars in their bank accounts. Refer to next question.
Why did you set cash contribition to 20.000€?
Because Nexedi has been spending more than 20.000€ per year to pay the salary of a Free Software developer who contributed to a software that is used on more than one million servers of some cloud unicorns after those same cloud unicorns refused to pay such a small amount. In other words. If Nexedi can pay such an amount, any company with cash should be able to.
Why do you ask proprietary software developers with no cash to advertise you company?
Because this helps us get cash to sponsor long R&D, which you will eventually benefit from.
What is the license of documentation?
Documentation that explains how to use our software is licensed under GFDL, a license that is approved by the Free Software Foundation.
Documentation that explains underlying abstractions, intentions or guidelines of Nexedi stack is licensed on CC-SA-NC, a proprietary license that is not approved by the Free Software Foundation but that lets Nexedi control content and prevent stealth rebranding missbehaviors which we had to face. In other words, Nexedi guidelines are not Free, just like the content of the GPLv3 license itself or certain works of RIchard Stallman are not Free.
Do I need to publish my software source code if I use GPL software?
No, you do not need. This is a hoax promoted by legal departments of some large proprietary software companies that also invented the bogus concept of "virality". In order to convince yourself, take an Android phone and ask yourself two questions:
Even though this phone is running a GPL licensed software - the Linux kernel - most software running on the phone is proprietary, including the baseband software which the Linux kernel relies on to establish Internet communication over the air.
What are my obligations then if I use Nexedi stack under GPLv3 license with exceptions?
You only need to provide access to improvements of Nexedi stack to any person that received a copy of Nexedi stack.
What are my obligations then if I use Nexedi stack under MIT license with exceptions?
Virtually none. This is why it is expensive.