The Books category contains APIs for book sharing, retail, social publishing, book creation, accessibility aids, book exchanges, metadata and more. This article focuses on 53 Books APIs including Readmill API and the popular Google Books API. We list 11 Google mashups along with other Books APIs.
If math is about measurement, then Mathletics may have your child's number. Much like games that post the best scores of players, the Mathletics SOAP API makes student scores accessible to programs as well as its website.
It's always exciting to see those outside the web industry using an API to improve their sites. NY Times First Look blog has a great example of what Dallas Public Library has done with the Best Sellers API.