From NLTK

NLTK is hosted on Sourceforge: http://sourceforge.net/projects/nltk

Browse the subversion repository

http://nltk.svn.sourceforge.net/viewvc/nltk/trunk/nltk/

Subversion

NLTK development uses a Sourceforge Subversion repository. To access the source tree, point your subversion client at https://nltk.svn.sourceforge.net/svnroot/nltk/trunk/nltk

Installing latest version

To install an up-to-the-minute version of NLTK, check out the subversion repository and run the setup.py script in the top directory (e.g. sudo python setup.py install; set the NLTK_DATA environment variable to point to the top level data directory.