# Natural Language Toolkit (NLTK)

NLTK -- the Natural Language Toolkit -- is a suite of open source Python
modules, data sets and tutorials supporting research and development in Natural
Language Processing.

For documentation, please visit [nltk.org](http://www.nltk.org/).


## Contributing

Do you want to contribute with NLTK development? Great! Please read more details
at [CONTRIBUTING.md](CONTRIBUTING.md).

See also [How to contribute to NLTK](http://www.nltk.org/contribute.html).


## Donate

Have you found the toolkit helpful?  Please support NLTK development by donating
to the project via PayPal, using the link on the NLTK homepage.


## Citing

If you publish work that uses NLTK, please cite the NLTK book, as follows:

    Bird, Steven, Edward Loper and Ewan Klein (2009).
    Natural Language Processing with Python.  O'Reilly Media Inc.


## Copyright

Copyright (C) 2001-2015 NLTK Project

For license information, see [LICENSE.txt](LICENSE.txt).

[AUTHORS.md](AUTHORS.md) have a list of everyone contributed to NLTK.


### Redistributing

- NLTK source code is distributed under the Apache 2.0 License.
- NLTK documentation is distributed under the Creative Commons
  Attribution-Noncommercial-No Derivative Works 3.0 United States license.
- NLTK corpora are provided under the terms given in the README file for each
  corpus; all are redistributable, and available for non-commercial use.
- NLTK may be freely redistributed, subject to the provisions of these licenses.
