From their site: ISBNdb.com's remote access application programming interface (API) is designed to allow other websites and standalone applications use the vast collection of data collected by ISBNdb.com since 2003. As of this writing, in July 2005, the data includes nearly 1,800,000 books almost 3,000,000 library records close to a million subjects hundreds of thousands of author and publisher records parsed out of library data more than 10,000,000 records of actual and historic prices. Using the API you can look up information by keywords, by ISBN, by authors or publishers, etc. In most situations the API is fast enough to be used in interactive applications.
The following is a list of libraries from ProgrammableWeb's Library Directory that matched your search term. Although there many different interpretations of the word "library" among software developers, ProgrammableWeb adheres to a specific definition so as to clearly distinguish libraries from SDKs and frameworks in a way that will facilitate clean search results. In ProgrammableWeb's parlance, the term "library" is strictly used to describe a platform-specific software tool that, when installed, results in the provisioning a specific API. Conversely, SDKs are exclusively for consuming APIs and Frameworks are agnostic to specific APIs. If you think a library, SDK, API, or other asset is missing from our directory, be sure to check our guidelines for making contributions to ProgrammableWeb.