Natural Language Processing tools

Here I will share some of the natural language processing(NLP) open source tools, information extraction, NER tools.

1. NLP Package

• NLTK:- . It is python package which is facilitated by many tools and resources.It is easy to use, as it is designed in python.It is provided with book and tutorial. The tools are mainly used for tagging, chunking, splitting, tokenizer and for other functions. It is also provided with resources and readers to interpet the resources.
• GATE:- The Gate is the java based tool which is mainly used for corpus creation(known as GATE document), chunking, tagging, NER and information extraction. Many packages and tools are plugged in with GATE. It supports pattern based grammars, so it can be used for languages which don't have much resources.It is used for corpus annotation, information extraction, NER, chunking, tagging(mainly grammar based pattern, which are written in java)
• Stanford package:- The package contains CRF based tagger, NER, topic modeling(using LDA) and classifier. The stanford parser gives both dependency and pharse structure parser output.
  
• Opennlp toolkit:- The tool kit is written in JAVA. It supports chunking, tagging and basic NLP application.
  
• Montylingua Package:- The package is used for chunking, tagging, splitting, tokenizing. Their claim is that they use common-sense which is in form of grammar. But their common sense is hard to understand at least for me. The package is provided with java and python.
  

• Mallet package:- It is machine learning toolkit for classification, Sequence tagging and topic modeling. Sequence tagger can be used for any type of tagging application. Topic Modeling tool uses LDA.
  

2. POS-Tagging

• MBT Tagger:- It is memory based tagger and generator.
• TreeTagger:-A decision tree based tagger from the University of Stuttgart (Helmut Scmid). It's language independent, but comes complete with parameter files for English, German, Italian, Dutch, French, Old French, Spanish, Bulgarian, and Russian. It uses language. It also uses lemma and other morph information to disambiguate the POS-tag.
  
• SVM Toolkit:- is tagger using SVM light. SVM is machine learning algorithm. It is trained on walt-street journal corpus.
  
• Accopost:- Open source C taggers originally written by by Ingo Schröder. Implements maximum entropy, HMM trigram, and transformation-based learning. C source available under GNU public license.
• MXPOST:- Java POS tagger. A sentence boundary detector (MXTERMINATOR) is also included
• FnTbl:- A fast and flexible implementation of Transformation-Based Learning in C++. Includes a POS tagger, but also NP chunking and general chunking models.
• MuTBl:- An implementation of a Transformation-based Learner (a la Brill), usable for POS tagging and other things by Torbjörn Lager.
• YamCha:-SVM-based NP-chunker, also usable for POS tagging, NER, etc. C/C++ open source. Won CoNLL 2000 shared task.
• Lingua Tagger:- Perl POS tagger.
• TnT POS tagger:- Trainable for various languages, comes with English and German pre-compiled models. The tagger uses vertibi algorithm for second order Marchov model.
  
• AMALGAM Tagger:- The AMALGAM Project also has various other useful resources, in particular a web guide to different tag sets in common use. The tagging is actually done by a (retrained) version of the Brill tagger (q.v.).

3. Named Entity Recongnation and Information Extraction:-

• Stanford NER:- A Java Conditional Random Field sequence model with trained models for Named Entity Recognition. Java. GPL. By Jenny Finkel.
• Lingpipe:-Tools include statistical named-entity recognition, a heuristic sentence boundary detector, and a heuristic within-document coreference resolution engine. Java. GPL. By Bob Carpenter, Breck Baldwin and co.
• ANNIE:-It is grammar based NER plus information extraction tool. It uses pattern based Grammar which is written in JAPE(Java language).
  
• OpenClasis:- Automated information extraction web service from Thomson Reuters (Free limited version)