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.