Information Extraction

• KEA (Keyphrase Extraction Algorithm) - New Zealand Digital Library, University of Waikato - open-source keyword/keyphrase extraction tool for text documents
  http://www.nzdl.org/Kea/
• PhraseRate (Keith Humphreys) - phrase extraction
  http://ivia.ucr.edu/projects/PhraseRate/
• WordHoard
  http://wordhoard.northwestern.edu