Natural Language Toolkit
About the Natural Language Tooklit (NLTK)
Open source Python modules, linguistic data and documentation for research and development in natural language processing and text analytics, with distributions for Windows, Mac OSX and Linux.
he NLTK project began when Steven Bird was teaching CIS-530 at the University of Pennsylvania in 2001, and hired his star student, Edward Loper, from the previous offering of the course to be the teaching assistant (TA). They agreed a plan for developing software infrastructure for NLP teaching that could be easily maintained over time. Edward wrote up the plan, and both began work on it right away.
Currently, the toolkit is used in a number of academic courses and is accompanied by a book written by the software architects Natural Language Processing with Python.