Description
GTK applications can reuse extra interface widgets that were not part of the standard toolkit at the time.
This legacy library is meant for developers or older applications that still depend on those custom widgets. It does not add a visible program for normal use; it supplies interface components that another application may need to build forms, entries, labels, or other controls.
Install it when an existing GTK application requires it. For new software, prefer current GTK widgets and maintained toolkit APIs.