The Bing Maps APIs include:
1: Bing Maps Ajax Control
The Bing Maps AJAX Control is a java script API that allows you to easily integrate maps and location functionality into your Web site. An Interactive SDK is also available at http://www.microsoft.com/maps/isdk/ajax, which offers hands-on, task-based demonstrations of features available in the version 6.3 map control release.
2: Bing Maps Silverlight Control
The Bing Maps Silverlight Control combines the power of Silverlight and Bing Maps to create an immersive mapping experience. You can find the Interactive Silverlight SDK at http://www.microsoft.com/maps/isdk/silverlight.
3: Bing Maps SOAP Service
The Bing Maps SOAP Services is a set of programmable SOAP services that allow you to integrate maps and imagery, driving directions, distance calculations, and other location intelligence into your applications, business processes, and Web sites.
4: Bing Maps REST Service
The Bing Maps REST Services can be used to perform tasks such as creating a map with pushpins, geocoding an address, retrieving imagery metadata or calculating a route.
5: Bing Spatial Data Services
The Bing Spatial Data Services includes the Geocode Dataflow API, which specifies URLs that you can use to geocode and reverse-geocode lists of spatial data.
More information please check MSDN site