Comment Map Authoring (Score 2, Informative) 84
If you want to be able to update you base layers:
-postgres with postGIS lets you store geometry (e.g lines/roads)
-GDAL/ORG with GRASS lets you author content
-openstreet maps in an opensource alternative to googlemaps that provides an API
-There are several geotagging/location modules in python that will take a lat/long and output an address