Libglade can be extended to support widget libraries built on top of GTK+. These modules are loaded dynamically at runtime. These modules are loaded when <requires> elements are found in the glade file.

Currently there are libglade module support for libbonoboui libgnomecanvas and libgnomeui. Note that libglade can also handle widgets that implement the properties interfaces with no extra code.

While no additional libglade initialisation is required to use a module, however, the underlying library might need initialisation. For instance, to use libgnomeui widgets from libglade, you must call gnome_program_init beforehand.