RubyLit - Ruby.del.litoral!
Usando Labels

require 'gtk2'

class Mi_app < Gtk::VBox
    def initialize()
        super()

        #defino una tabla para poner los labels
        tabla = Gtk::Table.new(1,8,false)

        label = Gtk::Label.new("label básico")
        tabla.attach(label,0,1,0,1)

        label = Gtk::Label.new("<span font_desc=\"Sans Italic 12\">Sans Italic 12</span>")
        label.use_markup = true
        tabla.attach(label,0,1,1,2)

        label = Gtk::Label.new("<span font_family=\"Serif\">font_family=Serif</span>")
        label.use_markup = true
        tabla.attach(label,0,1,2,3)

        label = Gtk::Label.new("<span size=\"x-large\">size=x-large</span>")
        label.use_markup = true
        tabla.attach(label,0,1,3,4)

        label = Gtk::Label.new("alineado derecha")
        label.set_alignment(1, 0)
        tabla.attach(label,0,1,4,5)

        label = Gtk::Label.new("alineado izquierda")
        label.set_alignment(0, 0)
        tabla.attach(label,0,1,5,6)

        label = Gtk::Label.new("<span foreground=\"blue\">Texto Azúl</span>")
        label.use_markup = true
        tabla.attach(label,0,1,6,7)

        label = Gtk::Label.new("<span background=\"blue\">Texto en fondo Azúl</span>")
        label.use_markup = true
        tabla.attach(label,0,1,7,8)

        pack_start(tabla, true)
    end
end

if $0 == __FILE__

class Viewer < Gtk::Window
  def initialize()
    super()
    set_title("Howto Label") 
    signal_connect("delete_event") { |i,a| Gtk::main_quit }
    set_default_size(250, 250)
    add(Mi_app.new)
  end
end

Gtk.init()

view = Viewer.new
view.show_all

Gtk.main()
end