Effective use of various Toolkit can help researchers get twice the result with half the effort.
The following NLP research toolkit is provided by NLP moderators.
At the same time, you are welcome to provide more useful toolkit to benefit NLP research in China.
* NLP 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
Opennlp http://opennlp.sourceforge.net/
* 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/
TNT http://www.coli.uni-saarland.de /~ Thorsten/TNT/
* English & Chinese 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
Chinese Emy of Sciences 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
Gibbslda + + http://gibbslda.sourceforge.net/
Glda http://code.google.com/p/glda/
* Conditional Random Fields
Flexcrfs http://flexcrfs.sourceforge.net/contains MPI parallel version.
CRF + + http://crfpp.sourFceforge.net/
CRF package http://crf.sourceforge.net/
CRFs MATLAB http://www.cs.ubc.ca /~ Murphyk/software/crfall.zip
Http://www.chokkan.org/software/crfsuite/ crfsuit
SGD with CRF http://leon.bottou.org/projects/sgd
Hcrf http://sourceforge.net/projects/hcrf/
* Support Vector Machine
Libsvm http://www.csie.ntu.edu.tw /~ Cjlin/libsvm/
Liblinear http://www.csie.ntu.edu.tw /~ Cjlin/liblinear/
Pegasos http://www.cs.huji.ac.il /~ Shais/code/index.html
* Search engines
Lucene Co http://lucene.apache.org/
Chinese Emy of Sciences firtex http://www.firtex.org/
* Machine learning and Data Mining toolbox
WEKA http://www.cs.waikato.ac.nz/ml/weka/
Common NLP tools