Lessons Learned
The MyMap API shows that Google Maps, Yahoo Maps, and Microsoft Virtual Earth provide similar features and similar ways of working. Displaying markers, geocoding, zooming, and moving the map are handled by similar methods in similar classes. Of course, we don't use all the features provided by these APIs. Each provider comes with some specific features; for example, Yahoo provides a great flash API, Microsoft offer a unique bird's eye view, and Google allows several tooltip customizations (including tabs).
Another difference between these APIs is the satellite and road-map coverage. Map details change from one country to the next depending on which map provider you choose. It's clearly a major difference when deploying markers outside major cities.
MyMap API shows that it's possible and not so complex to write a portable layer working either with Google Maps, Yahoo Maps, or Microsoft Virtual Earth. Using such an API, your mash-up application could take advantage of the best provider according to your own criteria (price, features, support, and the like), then take advantage from the intense competition between Google, Yahoo, and Microsoft.
The MyMap API presented here is licensed under LGPL, so you can use it freely on any open source or legacy project.
Acknowledgments
Thanks to Yacine Chahrour and Lisa Cree for giving me the official flight plan of Santa Claus and for their thorough reading and criticism of this article.
