Stanford CoreNLP provides a set of human language technology tools. It can give the base forms of words, their parts of speech, whether they are names of companies, people, etc., normalize dates, times, and numeric quantities, mark up the structure of sentences in terms of phrases and syntactic dependencies, indicate which noun phrases refer to the same entities, indicate sentiment, extract particular or open-class relations between entity mentions, get the quotes people said, etc.
A dependency parser analyzes the grammatical structure of a sentence, establishing relationships between "head" words and words which modify those heads.
OpenNLP is an organizational center for open source projects related to natural language processing. It hosts a variety of java-based NLP tools which perform sentence detection, tokenization, pos-tagging, chunking and parsing, named-entity detection, and coreference using the OpenNLP Maxent machine learning package.
Features
* (Jointly) visualize
o syntactic dependency graphs
o semantic dependency graphs (a la CoNLL 2008)
o Chunks (such as syntactic chunks, NER chunks, SRL chunks etc.)
* Compare gold standard trees to your generated trees (e.g. highlight false positive and negative dependency edges)
* Filter trees and visualize only what's necessary, for example
o only dependency edges with certain labels
o only the edges between certain tokens
* Search corpora for sentences with certain attributes using powerful search expressions, for example
o search for all sentences that contain the word "vantage" and the pos tag sequence DT NN
o search for all sentences that contain false positive edges and the word "vantage"
* Reads
o CoNLL 2000, 2002, 2003, 2004, 2006 and 2008 format
o Lisp S-Expressions
o Malt-Tab format
o markov thebeast format
* Export to EPS
Check this screenshot to get a better idea.
M. de Marneffe, B. MacCartney, und C. Manning. Proceedings of the IEEE / ACL 2006 Workshop on Spoken Language Technology, The Stanford Natural Language Processing Group, (2006)
M. de Marneffe, B. MacCartney, und C. Manning. Proceedings of the IEEE / ACL 2006 Workshop on Spoken Language Technology, The Stanford Natural Language Processing Group, (2006)
E. Charniak. Proceedings of the First Conference of the North American Chapter of the Association for Computational Linguistics (NAACL 2000), Seite 132--139. Seattle, Washington, Morgan Kaufmann Publishers, San Francisco, CA, USA, (April 2000)
R. Ge, und R. Mooney. Proceedings of the Ninth Conference on Computational Natural Language Learning (CoNLL-2005), Seite 9--16. Ann Arbor, Michigan, Association for Computational Linguistics, (Juni 2005)
E. Charniak. Proceedings of the First Conference of the North American Chapter of the Association for Computational Linguistics (NAACL 2000), April 29 - May 04, 2000, Seattle, Washington, Seite 132--139. Morgan Kaufmann Publishers, San Francisco, CA, USA, (2000)
T. Grenager, und C. Manning. Proceedings of the Conference on Empirical Methods in Natural Language Processing, The Stanford Natural Language Processing Group, (2006)