Geoadmingeocoder is a project mainly written in ..., it's free.
A geocoding attachment to the geodjango geographic admin application
2011-07-05 Bill Morris
provides a geocoder for the "Add Feature" function in a modified version of the geodjango geographic administrator application
A stripped-down django backend for calling to geocoding services, including
A simple address dialog built on top of the geographic_admin (http://code.google.com/p/geodjango-basic-apps/wiki/GeographicAdminQuickStart) map when adding a new feature to any existing layers