Comments on Copyright and License

QuantLib is Non-Copylefted Free Software [1] released under the modified BSD License [2] (also know as XFree86-style license).

QuantLib is Open Source [3] because of its license: it is OSI Certified Open Source Software [4]. OSI Certified is a certification mark of the Open Source Initiative [5].

The modified BSD License is GPL compatible as confirmed by the Free Software Foundation [6].

This license has been adopted to allow free use of QuantLib and its source, to make QuantLib flourish as a free-software/open-source project. It allows proprietary extensions to be commercialized.

[1] http://www.gnu.org/philosophy/categories.html#Non-CopyleftedFreeSoftware
[2] http://www.opensource.org/licenses/bsd-license.html
[3] http://www.opensource.org/docs/definition.html
[4] http://www.opensource.org/docs/certification_mark.html
[5] http://www.opensource.org
[6] http://www.gnu.org/philosophy/bsd.html