MapQuest are best known as one of the pioneers of public online mapping. In recent years they have lost market share to Google and Microsoft, but have responded by producing their "Platform Services" in the form of a Tile Map Toolkit and public API.
MapQuest started life in 1967 as Cartographic Services, a division of R.R. Donnelley & Sons; and supplied paper maps. They were spun off as an independent company in 1994 with the new name of GeoSystems Global Corporation. The division had started to use computers to generate their paper maps in the mid-1980s, and this software was adapted to create their first online map services in 1996. GeoSystems was rebranded as MapQuest in 1999, and was acquired by America Online in 2000. The traditional publishing division was finally sold in October 2006.
MapQuest became very popular for public map directions, and regularly appeared on business website "where we are" pages. However, in recent years MapQuest has lost market share to Google and Microsoft who have produced visually more appealing products. MapQuest appeared slow to adopt an AJAX architecture, resulting in an interface that appeared sluggish compared to the competition. They were also slow to realize the marketing potential of including high resolution satellite images. People were not passing MapQuest URLs of their home, interesting locations, etc.
As well as basic map display, the API includes pushpin/icon locations, geocoding, route finding, object collections, shape overlays, custom tile layers, and external GeoRSS & KML feeds. A declutter mode allows a map to be "de-cluttered" by replacing multiple icons with a special "declutter" icon. Batch geocoding is also supported, and allows for up to 100 addresses to be geo-coded at once.
MapQuest also features a native Traffic Control. This displays traffic status reports as an overlay and can be customized in a number of ways. This is a feature that is currently only available on Google Maps and Virtual Earth from third parties.
Here is the code that produced the above image:
ERROR [include_code_listing plugin]: File Not Found (/usr/www/users/winwaed/geowebguru/img/2009/mapquest_example.html)
The traffic control is implemented in only one line, although further customization could be added if required.
As can be seen on the above map, MapQuest supports road maps, satellite imagery, and hybrid maps. MapQuest does not currently support street view or bird's eye views. I looked at three different areas and found the satellite imagery to be generally lower resolution and/or older than similar coverage in Google Maps or Virtual Earth. In my comparisons, I found urban US imagery of Irving TX to be about 2-3 years old and lower resolution (just sufficient to identify cars in known driveways). Resolution of North Wales was lower and had poor color contrast with an over-saturated green channel. North Wales also included a small amount of cloud cover. Both Google and Microsoft have cloud free, high resolution imagery of North Wales. For rural Costa Rica, I found that Mapquest uses the exact same image tile as Google Maps and Virtual Earth - this is easily recognizable by the cloud patterns. All three only include regional roads.
So to summarize, MapQuest are playing catch-up to developments by Microsoft and Google, but lead in some areas. MapQuest advantages include a much wider range of API languages, and a native traffic control.
To use the MapQuest API, you will need a developer's key. The key can further information on MapQuest's API can be found at the MapQuest Developers Network ( http://developer.mapquest.com/home ).