Libchamplain is a C library providing a ClutterActor to display maps. It also
provides a Gtk+ widget to display maps in Gtk+ applications. Mono, Python and
Perl bindings are available.

It supports numerous free map sources such as OpenStreetMap [1], 
OpenAerialMap [2] and Maps for free [3].
[1] http://www.openstreetmap.org/ [2] http://www.openaerialmap.org/
[3] http://www.maps-for-free.com/

WWW: http://projects.gnome.org/libchamplain/