The Bookboon .Net SDK by Bookboon is a Microsoft .Net wrapper for use with the Bookboon.com API. The Bookboon API makes bookboon.com books available to 3rd parties that want to have bookboon books integrated into their own applications. The API provides tools for categorizing, browsing, and searching.
The API for this English-language news hub for Anime and Magna provides a direct news feed for the site's encyclopedia data, that is stored in XML format. The Anime News Network Encylopedia API provides both top level reports on titles and then drills down to provide details on them, for up to 50 requests at a time.
For the developer seeking to experiment efficiently with social APIs, O'Reilly's 2nd Edition of "Mining the Social Web" is a truly outstanding resource.
Author Matthew A. Russell drops the developer right into the sandbox of each social network (Twitter, Facebook, LinkedIn and Google+ are particularly emphasized, as you would expect) with just the right amount of explanation about what's accessible via each dataset, and then clears out all the obstacles so they can start data mining against very clear examples.