License? MPFR C++ is GPL

[cxw42]

I agree with your choice of the MPL license. However, I see from http://www.holoborodko.com/pavel/mpfr/#license that MPFR C++ is GPL (apparently GPL 3), unless you make other arrangements with the author. I am not a lawyer, but my impression was that code linking with GPL had to be licensed GPL or compatible. Do you have any information about MPL vs. GPL?

Related to #7, is it possible to build without MPFR C++? I see that NumericalIntegration.h unconditionally includes <unsupported/Eigen/MPRealSupport> --- could that be removed for a non-MPFRC++ version?

[mcsauder]

Hi @cxw42 ,

I agree with your choice of the MPL license. However, I see from http://www.holoborodko.com/pavel/mpfr/#license that MPFR C++ is GPL (apparently GPL 3), unless you make other arrangements with the author. I am not a lawyer, but my impression was that code linking with GPL had to be licensed GPL or compatible. Do you have any information about MPL vs. GPL?

With some research and without previous intent to the opposite, @cxw42 , your point is valid, however it was not without conversing and advice from the author, so it was not with malicious intent.

@advanpix , what are your thoughts here and what would you like to happen?
I apologize if I neglected your wishes in license. given my previous understanding this was not how I thought the licenses played together. However, at this point I do believe the issue raised is correct. How would you like to see it through?

Thank you for all of your input!

-Mark

[mcsauder]

NOTE We also worked closely with Dr John Burkhardt of the University of South Florida on his porting of QUADPACK back in 2012-2014, but I an am failing to locate/contact him at this point after some web searching.

[advanpix]

As the author of MPFR C++ I confirm that there is no license conflicts, as I personally agreed for MPFR C++ to be distributed with Eigen and this library under MPL. The only exception is commercial usage of MPFR C++: this requires special commercial license.

I am not sure if this plays well with the intention of the authors of the library.

[cxw42]

@advanpix Thank you very much for the response and confirmation! Just to make sure:

• If I use this library, but do not directly use MPFR C++, the license is MPL regardless of whether the usage is commercial.
• If I use this library and also directly use MPFR C++, the license is GPL for non-commercial use, and commercial use is not permitted without a special license.

Am I understanding you correctly? Much appreciated!