ABNER is a software tool for molecular biology text analysis. At ABNER's core is a statistical machine learning system using linear-chain conditional random fields (CRFs) with a variety of orthographic and contextual features. It also has a UI for annotat

The Baseline Information Extraction (BALIE) system is a Java natural language toolkit developed at the University of Ottawa and released under the GNU General Public License. BALIE provides language ID, sentence detection, part of speech and named-entity

FreeLing is a set of C++ tools developed at the Universitat Politècnica de Catalunya and released under the GNU Lesser General Public License. Freeling provides sentence detection, morphological analysis, named entities, POS tagging, shallow parsing, depe

MontyLingua is a free*, commonsense-enriched, end-to-end natural language understander for English. Feed raw English text into MontyLingua, and the output will be a semantic interpretation of that text. Perfect for information retrieval and extraction, re

An extensive package developed at Northwestern for spelling, lemmatization, sentence detector, part-of-speech tagger, named entity detector, and phrase chunker. It rolls in many other projects into a coherent and well-documented package. Mainly aimed at h

The Natural Language Toolkit (NLTK) is a general Python toolkit developed at the University of Melbourne for natural language processing released under the GNU General Public License. NLTK contains open source Python modules, linguistic data and documenta

OpenNLP provides the organizational structure for coordinating several different projects which approach some aspect of Natural Language Processing. OpenNLP also defines a set of Java interfaces and implements some basic infrastructure for NLP components.

Protégé is a free, open source ontology editor and knowledge-base framework.