gistfile1.txt

#!/bin/ruby

require 'gtk3'

class RubyApp < Gtk::Window

  def initialize
    super

    grid = Gtk::Grid.new
    grid.set_property "row-homogeneous", true
    grid.set_property "column-homogeneous", true
    grid.attach Gtk::Button.new(:label => "Information"), 0, 0, 1, 1
    grid.attach Gtk::Button.new(:label => "Software"), 1, 0, 1, 1
    grid.attach Gtk::Button.new(:label => "Maintenance"), 2, 0, 1, 1
    grid.attach exitbutton = Gtk::Button.new(:label => "Exit"), 3, 0, 1, 1
    exitbutton.signal_connect "clicked" do
      Gtk.main_quit
    end

    add grid

    set_title "Prototype"
    signal_connect "destroy" do
      Gtk.main_quit
    end

    set_default_size 300, 100
    set_window_position(Gtk::Window::Position::CENTER)

    show_all

  end

end

Gtk.init
    window = RubyApp.new
Gtk.main