# File gtk/sample/gtk-demo/appwindow.rb, line 161
    def about_cb(*args)
      unless Gtk.check_version?(2, 6, 0)
        puts "This sample requires GTK+ 2.6.0 or later"
        return
      end

      authors = ["Peter Mattis", "Spencer Kimball", "Josh MacDonald", "and many more..."]
      documentors = ["Owen Taylor", "Tony Gale", "Mattias Clasen <mclasen@redhat.com>",  
        "and many more..."]
      license = %Q[
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the Gnome Library; see the file COPYING.LIB.If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
]

      transparent = Gdk::Pixbuf.new(Demo.find_file("gtk-logo-rgb.gif")).add_alpha(true, 0xff, 0xff, 0xff)
      
      Gtk::AboutDialog.set_email_hook {|about, link|
        puts "send mail to #{link}"
      }
      Gtk::AboutDialog.set_url_hook {|about, link|
        puts "show url #{link}"
      }
      Gtk::AboutDialog.show(self,
                            :name => "GTK+ Code Demos",
                            :version => Gtk::VERSION.join("."),
                            :copyright => "(C) 1997-2004 The GTK+ Team",
                            :license => license,
                            :website => "http://www.gtk.org",
                            :comments => "Program to demonstrate GTK+ functions.",
                            :authors => authors,
                            :documenters => documentors,
                            :logo => transparent)
    end