"Connected Histories will create a federated search facility for a wide range of distributed electronic resources relating to early modern and nineteenth-century British History. Through a combination of web crawling and the application of Natural Language Processing methodology the project will create a non-intrusive, distanced tagging of the data within those distributed sources to facilitate more sophisticated and structured searching"
http://www.jisc.ac.uk/whatwedo/programmes/digitisation/econtent/connectedhistories.aspx