Third party documentation

NLTK Essentials - Build cool NLP and machine learning applications using NLTK and other Python libraries by Nitin Hardeniya

Python 3 Text Processing with NLTK 3 Cookbook - Over 80 practical recipes on natural language processing techniques using Python's NLTK 3.0 by Jacob Perkins

Python Text Processing with NLTK 2.0 Cookbook - lots of text processing recipes by Jacob Perkins

http://text-processing.com/demo/ - interactive online demos by Jacob Perkins

NLTK posts at Streamhacker.com - more text processing recipes by Jacob Perkins

Building a NLTK FreqDist on Redis - improved FreqDist using an efficient key-value network-accessible database

Chunk Extraction with NLTK - creating parse trees from unstructured text

Corpus Processing and Tokenizing with NLTK - introduction to basic corpus operations

Distributed NLTK with Execnet - distributed part-of-speech tagging

Execnet vs Disco for Distributed NLTK - comparing platforms for distributed data processing

How to Train a NLTK Chunker - training a chunker (features accuracy results)

How to Use an NLTK Part-of-Speech Tagger - basic information

The Python and the Elephant: Large Scale Natural Language Processing with NLTK and Dumbo - PyCon 2010 talk by Nitin Madnani and Jimmy Lin

Integrating NLTK with the Hadoop Map Reduce Framework - a programming model for writing applications that rapidly process vast amounts of data in parallel on large clusters of compute nodes

NLTK Classifier Based Chunker Accuracy - comparing performance of chunkers based on taggers vs classifers

NLTK Regular Expression Parser - basic information on RegexpParser usage

Part of Speech Tagging with NLTK - Part 1, Part2, Part 3, Part 4 (Brill Tagger vs Classifier Taggers)

Processing Corpora with Python and the Natural Language Toolkit - tutorial

Tagging with NLTK - constructing and evaluating POS taggers

Using NLTK with C#

Analyzing CHILDES with NLTK - processing child language data

Sentiment analysis in Python with NLTK