Last.fm Lib .Net is a code library for the Last.fm API written in VB.Net 2008, but it can also be used with C# and ASP.NET. It provides a complete implementation of versions 1.0 and 2.0 of the API, the Radio API, and the Audioscrobbler 1.2.1 protocol.
The LPFM Last.fm Scrobbler is a .NET library for accessing the Last.fm API from desktop, web, or mobile applications. Specifically, the library supports the Scrobble, Now Playing, Love/Unlove, and Ban/Unban functionalities from version 2.0 of the API.
The Bing REST Client is a library for accessing the Bing Maps and Bing Spatial APIs. Eventually, the library will enable users to access all of Bing's public APIs. The Bing REST Client works with .NET 4.5, Windows Phone 8, Windows 8.x, Android, and iOS.
FlickrNet is a .NET library for implementing all of the Flickr API's methods. It is designed to reduce the complexity of calling the API, especially with regards to authentication. This library can be accessed from a variety of frameworks and is written entirely in C#.
Microsoft Opens Xbox Music API, Affiliate Program to Third-Party Developers
The Betaface SDK, with Face Detection and Recognition, is a Windows DLL library that applies complex algorithms designed to detect a set of pre-programmed facial characteristics within images as well as videos. These features include general face info such as position, size, angle, 8 standard facial landmarks, gender, age ethnicity, and more. Extended measurements can include more detailed specific information like facial hair, glasses, hairstyle, skin color, clothes, background color, and more. The SDK can be accessed from multiple environments, as long as a call is made to DLL, COM object, or .Net.
For detailed information see http://betaface.com/wpa/wp-content/uploads/2014/01/Betaface-SDK.pdf