Digital Cartography

Your excellent cover story ("Killer Maps," October 2005) captured the developing landscape of competition between the likes of Google, Microsoft, and Yahoo over new location-based browsing, searching, and visualization. It's appropriate you began the article by describing the highly interactive nature of Google Earth and its 3-D interface for showing the earth.

Although mapping applications like Microsoft's Virtual Earth and Yahoo Maps have APIs for customization, Google Earth uses a standardized XML-like interface allowing both simple and complex database enhancements, which tens of thousands of people have used to share many new innovative data sources, among them 3-D flight tracking, spread of avian flu, and collections of panorama images.
Frank Taylor
Raleigh, NC