The Calais Web Service ingests unstructured text and returns Resource Description Framework formatted results identifying entities, facts and events within the text.[4] The service appears to be based on technology acquired when Reuters purchased ClearForest in 2007.
DBpedia Spotlight is a tool for annotating mentions of DBpedia resources in text, providing a solution for linking unstructured information sources to the Linked Open Data cloud through DBpedia. DBpedia Spotlight performs named entity extraction, including entity detection and Name Resolution (a.k.a. disambiguation). It can also be used for building your solution for Named Entity Recognition, amongst other information extraction tasks.
Imagine you can see 160 years of history, all on one screen. You can zoom and pan, you can look at a particular day, you can even do a search. And when you do, the results come up not as a list, but as a heat map that shows where in history that topic appears, and how often.
G. Forman, and E. Kirshenbaum. CIKM '08: Proceeding of the 17th ACM conference on Information and knowledge management
, page 1221--1230. New York, NY, USA, ACM, (2008)