Libre Licenses

Each piece of material on this website is individually copyrighted by its own author. However the global approach is to allow everybody to freely use it all, and apply the concept of copyleft to guarantee the same degree of freedom is preserved in derivative works. This is achieved thanks to the Creative Commons and GNU GPL licenses, as described below.

Creative Material

Unless otherwise specified and with the exception of software, you can freely use, perform, make copies and share all the material available on this website for non-commercial purposes. You can also use it again in your own personal stuff, as long as you keep the same license for your own derivative works. To be precise, everything here is made available under the terms of the Creative Commons BY-NC-SA license which is the short name for Attribution Non-Commercial Share-Alike.

Important: This license does not permit commercial use of the material, but you may obtain a special authorization from the authors. Please get in touch by e-mail to discuss the matter.


Unless specified otherwise, all software on this website is distributed under the terms of the GNU GPL license. This means it's free software, and derivative works must also be distributed under the terms of the GPL license.

Of course writing good software requires a great deal of creativity, but a software programme is more a tool providing means of producing original material than a finality in itself. Material generated by a free software programme belongs entirely to the user of the programme, who is free to license and distribute the generated material under the license terms of their choice (or keep it for themselves).

The GPL license is also more appropriate for distributing software than Creative Commons licenses.