Semantinet’s slogan, “Information into knowledge” aptly describes their work. Semantinet is building a giant information graph of people, places and concepts linked together by whichever relationships are detected from both structured and unstructured data sources on the web. It’s a simple thing to describe, but the implications are profound. This type of information technology is so much more powerful than a collection of articles that can be searched by keyword. What we have here resembles how we imagine information and memories are stored in our own minds, and its available to be used in your own project through the Semantinet Knowledge Graph API.
Wolfram Alpha, the up-and-coming "answer engine" that we reported on back in May, has just released an API that developers have been awaiting since this spring. The new RESTful API provides access to the vast stores of data and computational knowledge available through the Wolfram Alpha project (technical details at our Wolfram Alpha API profile).
As the national library of the United States, the Library of Congress has created vast amounts of metadata to describe books and other documents in its collection. Among this metadata is the Library of Congress Subject Headings (LCSH), a "controlled vocabulary" for classifying documents by subject.