GTK+, The GIMP ToolKit

Cross-platform Graphical User Interface library

Website: http://www.gtk.org
Platforms supported: Win32, Linux
Headers to include: gtk/gtk.bi
Example Usage: yes, in examples/GUI/GTK+/
Header version: 2.24.27, 3.14.10

By default, gtk/gtk.bi will use the GTK+ 2 API.
Define __USE_GTK3__ before including gtk/gtk.bi to use GTK+ 3.

Example
   #include Once "gtk/gtk.bi"

   Dim Shared As GtkWidget Ptr win

   Private Sub on_clicked cdecl(ByVal button As GtkButton Ptr, ByVal userdata As gpointer)
      Static As Integer clickcount = 0
      clickcount += 1
      gtk_window_set_title(GTK_WINDOW(win), "clicked " & clickcount & " times")
   End Sub

   gtk_init(NULL, NULL)

   win = gtk_window_new(GTK_WINDOW_TOPLEVEL)
   gtk_window_set_title(GTK_WINDOW(win), "A small GTK+ example")
   gtk_window_set_default_size(GTK_WINDOW(win), 300, 200)
   gtk_container_set_border_width(GTK_CONTAINER(win), 20)

   g_signal_connect(G_OBJECT(win), "destroy", G_CALLBACK(@gtk_main_quit), NULL)

   Dim As GtkWidget Ptr button = gtk_button_new_with_label("Click me!")
   gtk_container_add(GTK_CONTAINER(win), button)

   g_signal_connect(G_OBJECT(button), "clicked", G_CALLBACK(@on_clicked), NULL)

   gtk_widget_show_all(win)

   gtk_main()

