ArcGIS API for Microsoft Silverlight/WPF
ESRI
The ArcGIS API for Microsoft Silverlight/WPF provides the necessary components to add maps and geographic information systems (GIS) capabilities into cross-browser and cross-platform rich Internet applications (RIA). The API enables you to consume services from ArcGIS Server, ArcGIS Online, and Bing Maps for Enterprise in desktop and Web applications. You can create interactive and expressive Web applications leveraging ArcGIS Server services such as maps, image, geocoding, routing/directions, as well as execute GIS anaylis using geoprocessing tasks.