A dual license system for code libraries?
agner at agner.org
Sat Feb 25 08:54:39 UTC 2017
Hi, I have a problem with several open source projects. Neither GPL nor
LGPL license seems to be appropriate.
One such project is my C++ vector class library
Right now, I am using a dual license system. The library is published
under GPL, following the advice at
However, there is a significant demand for using this library in
commercial closed-source code. Therefore, I am selling commercial
licenses to anybody who want to use the library in commercial code.
Now, there is a problem with unifying the copyright. I want to put this
code on github and make it a collective project. But then I can no
longer be the only copyright owner. It is not fair that others should
contribute to the project for free while I make profit on selling
licenses. We would have to set up an organization to own the copyright
and sell licenses. But the administration cost of running such an
organization would probably eat up all the income. And open source
programmers prefer to spend their time on programming, not on
administration of an organization.
An LGPL license is not possible because the program code that uses a
class library will be a "derived work", not a "combined work", and it is
impossible to meet the relinking requirement of LGPL. The application
code and class library code are mixed together and compiled together so
that the two cannot be separated.
An Apache or BSD license might be possible, but I don't think commercial
users like the requirement that the end product should include various
required notices. Also, I think these licenses are too permissive. I
like the protection against tivoization, DRM, and patent retaliation in GPL.
More importantly, people would have little motivation to contribute to
an open source library when their work only goes to somebody else's
profit. The motivation would be higher if the effort could somehow
contribute to the general goal of supporting free software. That's why I
prefer the dual license solution. The only problem is who should own the
copyright and sell commercial licenses?
I have asked the FSF, but they are not willing to sell licenses, and
frankly they are quite difficult to communicate with. That's why I am
now taking the discussion to FSFE. Is there any other suitable
non-profit organization who could be the copyright owner and sell licenses?
I have also thought about a scheme that requires no administration. You
would get a commercial license automatically by donating a certain
amount of money to some non-profit organization and posting proof of
payment to some repository. Would that work?
Or do we need a completely new license concept for open software
libraries and other code that is likely to be used in proprietary
derived works? Any suggestions?
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