sidef/scripts/Graphical/hello_world_graphical_1.sf

#!/usr/bin/ruby

#
## https://rosettacode.org/wiki/Hello_world/Graphical
#

use('Gtk3 -init')

var gtk3   = %O'Gtk3'
var window = %O'Gtk3::Window'.new
var label  = %O'Gtk3::Label'.new('Goodbye, World!')

window.set_title('Goodbye, World!')
window.signal_connect(destroy => { gtk3.main_quit })

window.add(label)
window.show_all

gtk3.main