Although they are not really first-class objects (there are no actual metatypes in GType), metaobjects like classes and interfaces are created by GObject applications at runtime, and provide good support for introspection. The introspective capabilities are used by language bindings and user interface design applications like Glade to allow doing things like loading a shared library that provides a GObject class—usually some kind of widget, in the case of Glade—and then obtain a list of all properties of the class, complete with type information and documentation