[Tux4kids-discuss] TuxMath Application!

[Sam Toyer]

Hi Juan, I'm not a Tux4Kids developer---in fact, I'm not sure why I'm 
even subscribed to this list! Nonetheless, I think I might be able to 
clear some things up for you.

On 15/10/13 12:29, Juaan Martiinez Blanco wrote:
> I mean, I need your authorization for use your images and take you
> main idea about how the game works, because I want to do a program
> but taking your idea, what I would like to do is like the same game
> but with new functionality

Like Pere said, the code and data in TuxMath is mostly licensed under 
the GNU GPL (in this case, it's v2 or v3 of the license). Pretty much 
every question you could possibly ask about he GPL is covered in the 
"GPL FAQ"[0]. As a "Free Software" license, the GPL grants you the 
following freedoms:

Freedom 0:
The freedom to run the program for any purpose.

Freedom 1:
The freedom to study how the program works, and change it to make it do 
what you wish.

Freedom 2:
The freedom to redistribute copies so you can help your neighbor.

Freedom 3:
The freedom to improve the program, and release your improvements (and 
modified versions in general) to the public, so that the whole community 
benefits.

However, if you decide to release your software to the public (by 
putting it on Google Play, for instance), the GPL also requires 
(roughly) that you also grant your users the four freedoms listed above 
(which usually means that you have to release *all* of your source code 
to them under a GPL-style license). This is covered in more detail in 
the GPL FAQ, as well as being written out in painful (but precise) 
legalese in the license itself.

The specific licensing arrangements for every single one of the images, 
sounds and other assets are documented by ``doc/README_DATA_LICENSES`` 
in the TuxMath source, which you can browse right now at [1] if you so 
desire. Likewise, the data which makes up the story is covered under 
those licenses.

> Please I beg you, give me your authorization, it is for my project and I
> will be forever grateful with you.

You probably won't be able to get *direct* authorisation from the 
Tux4Kids developers because they don't seem to be active on this mailing 
list at the moment. Don't let that deter you, though. What you've 
outlined---writing an Android game using the TuxMath story and 
images---seems entirely within your rights under the GNU GPL, so you 
shouldn't need direct authorisation. To quote Pere:

> I think the GNU/GPL V3 license already grants you that authorization,
> read it please :)

Good luck with your project!

[0] https://www.gnu.org/licenses/old-licenses/gpl-2.0-faq.html
[1] http://anonscm.debian.org/gitweb/?p=tux4kids/tuxmath.git;a=tree;hb=HEAD