An icon from Tango Project. Since version 0.8.90 Tango Project icons are Public Domain. tango icon software Tango Software Update Available
"Software update" icon from Tango Project Since version 0.8.90 Tango Project icons are Public Domain: Tango Project FAQ tango icon earh Tango System Software Update
Gimp Icon "ghnomix" from here:http://ilnanny.deviantart.com/art/update-ghnomix-1-3-283689300 this icon is part of my icon theme for linux icons Gimp