The gtk+-devel package contains the static libraries and header files
needed for developing GTK+ (GIMP ToolKit) applications. The
gtk+-devel package contains glib (a collection of routines for
simplifying the development of GTK+ applications), GDK (the General
Drawing Kit, which simplifies the interface for writing GTK+ widgets
and using GTK+ widgets in applications), and GTK+ (the widget set).
This package is a beta version of the next release of GTK+.
You should only install this package if you are a developer
who wants to start developing against the new version of GTK+.