require 'gtk'

window = Gtk::Window.new(Gtk::WINDOW_TOPLEVEL)
clist = Gtk::CList.new(['name', 'value'])
clist.set_usize(300, 200)
clist.set_column_width 0, 100
ENV.keys.sort.each {|k| clist.append [k, ENV[k]]}
window.add clist
clist.show
window.show
Gtk.main