(gnome gnome) wraps some pieces of the libgnome library for
Guile. It is a part of Guile-GNOME.
Libgnome historically was a staging ground for code meant to go elsewhere. In the modern environment, it has largely been replaced, its functionality having been pushed into GLib, GTK+, and other lower-level libraries.
However, as of 2008 it still has some utility. The help functions are
useful. (gnome gnome) wraps those parts that have not been
replaced yet.
See the documentation for (gnome gobject) for more information
on Guile-GNOME.