~Windows~ are toplevel container widgets that are affected by the window manager parameters, e.g. dialog boxes, popups, application windows, etc. To set a window's title: set_title('My App'); ?>]]> To set the focus widget in the window: set_focus($name_entry); ?>]]> To set the default widget in the window (note that the widget has to call %can_default()% first): set_default($ok_button); ?>]]> To inhibit interaction with other windows in the same app, make it ~modal~, disallow lowering it below the parent window, and run a new main loop: set_modal(true); $dialog->set_transient_for($parent); gtk::main(); ?>]]>