The Crystal Clear icons are licensed under the GNU Lesser General Public License (LGPL).
http://commons.wikimedia.org/wiki/Crystal_Clear
http://en.wikipedia.org/wiki/GNU_Lesser_General_Public_License


The Deleket Deviantart icons are licensed under a Creative Commons Attribution-Noncommercial 3.0 License.
http://deleket.deviantart.com/art/Button-Icons-Pack-58987743?q=gallery%3Adeleket%20randomize%3A1&qo=1
http://creativecommons.org/licenses/by-nc/3.0/

The sekkyumu icons are licensed under a Creative Commons Attribution-Noncommercial 3.0 License.
http://sekkyumu.deviantart.com/art/Developpers-Icons-63052312

The imacadam icons are licansed unter a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0
http://www.imacadam.com/

Cloud icon is Free for non commercial use.
Author: http://www.stardock.com/weather.asp

Oxygen Icons are licensed under a GNU Lesser General Public License.
http://www.oxygen-icons.org
http://en.wikipedia.org/wiki/GNU_Lesser_General_Public_License

IronDevil:
License: Free for non-commercial use.