NLP常用开源/免费工具

一些常见的NLP任务的开源/免费工具，

*Computational Linguistics Toolbox
CLT http://complingone.georgetown.edu/~linguist/compling.html GATE http://gate.ac.uk/ Natural Language Toolkit(NLTK) http://nltk.org MALLET http://mallet.cs.umass.edu/index.php/Main_Page
*English Stemmer
Snowball http://snowball.tartarus.org/
*English POS Tagger
Stanford POS Tagger http://nlp.stanford.edu/software/tagger.shtml TreeTagger http://www.ims.uni-stuttgart.de/projekte/corplex/TreeTagger/
*English Parser
Stanford Parser http://nlp.stanford.edu/software/lex-parser.shtml Berkeley Parser http://nlp.cs.berkeley.edu/Main.html#Parsing
*English Keyphrase Extractor
KEA http://www.nzdl.org/Kea/index_old.html
*English Name Entity Recognizer
Stanford NER http://nlp.stanford.edu/software/CRF-NER.shtml
*Chinese Word Segmentator
中科院ICTCLAS http://www.nlp.org.cn/project/project.php?proj_id=6 Stanford Word Segmenter http://nlp.stanford.edu/software/segmenter.shtml
*Topic Modeling Tools
Matlab http://psiexp.ss.uci.edu/research/programs_data/toolbox.htm
*Machine Learning Methods
CRF++ http://crfpp.sourceforge.net/ LIBSVM http://www.csie.ntu.edu.tw/~cjlin/libsvm/
*Search Engines
Lucene http://lucene.apache.org/ 中科院FirteX http://www.firtex.org/
*Data Mining Toolbox
Weka http://www.cs.waikato.ac.nz/ml/weka/