GNOME (GNU Network Object Model Environment) is a user-friendly set of GUI applications and desktop tools to be used in conjunction with a window manager for the X Window System. The libgnomeui-devel package includes the libraries and include files that you will need to use libgnomeui.

You should install the libgnomeui-devel package if you would like to compile GNOME applications. You do not need to install libgnomeui-devel if you just want to use the GNOME desktop environment.