If you're a developer looking to supplement your own data tools and services, this concise ebook covers the most useful sources of public data available today. You'll find useful information on APIs that offer broad coverage, tie their data to the outside world, and are either accessible online or feature downloadable bulk data. You'll also find code and helpful links. This guide organizes APIs by the subjects they cover-such as websites, people, or places-so you can quickly locate the best resources for augmenting the data you handle in your own service. Categories include: * Website tools such as WHOIS, bit.ly, and Compete * Services that use email addresses a search term, including Github * APIs for finding information from just a name, including WhitePages * Services that help you locate people with accounts, such as Klout * Search APIs, including BOSS and Wikipedia * Geographical data sources, including SimpleGeo and US Census * Company information APIs, such as CrunchBase and ZoomInfo * APIs that list IP address, such as MaxMind * Services that list books, films, music, and products