AGTK A suite of software components for building tools for annotating linguistic signals, time-series data which documents any kind of linguistic behavior (e.g. audio, video). The internal data structures are based on annotation graphs.

Arithmetic Coding A java package Arithmetic Coding and PPM (adaptive variable-length > n-gram language models for compression)

ComLinToo A set of Perl tools for computational linguistics (esp. corpus handling and (permutation) statistics).

Attribute-Logic Engine (ALE) A freeware logic programming and grammar parsing and generation system

EDG A Lisp system for developing and displaying HPSG

Ellogon An LGPL component-based natural language engineering platform written in C, C++, Java, Tcl, Perl, and Python

Emdros A text database engine for analyzed or annotated text.

FreeLing An open source suite of language analyzers.

GuiTAR A General Tool for Anaphora Resolution.

Heart of Gold Middleware for combining shallow and deep NLP components.

Leo A project to provide an architecture for defining XML specifications of grammars for different natural language parsing systems and tools for converting grammars automatically between those systems

LKB The LKB system is a grammar and lexicon development environment for use with constraint-based linguistic formalisms.

Mallet A Machine Learning for Language Toolkit written in Java

MinorThird A collection of Java classes for storing text, annotating text, and learning to extract entities and categorize text.

Ngram Statistics Package Allows for the counting and measuring of Ngrams in text.

NLTK A Python package intended to simplify the task of programming natural language systems.

nlpFarm A collection of NLP libraries, tools and demo applications. Current focus is mainly on parsing and dialogue systems.

SenseRelate Implements a word sense disambiguation algorithm using WordNet::Similarity

Tiger API Library which allows java programmers to easily access the structure of any corpus given as a tiger-xml file.

Web as Corpus Toolkit A collection of programs that can be used to create a (large) text corpus from a list of URLs.

Weka A collection of machine learning algorithms for data mining tasks.

Weta The Waikato Environment for Text Analysis