This icons set ("331 icons") is licensed under GNU 
General Public License (GPL) license 2.0 :
http://creativecommons.org/licenses/GPL/2.0/

Basically, you can do almost anything you want with them 
(give them away, sell them, modify them, etc.) BUT CANNOT 
claim this is your work.

You should also include a copy of the GPL license or a link 
to it with any distribution.



Copyright holder is Pablo Fabregat.
http://www.opentux.com.ar/lordcrow/packs/kneu.html