Natural Language Processing in Python by Steven Bird, Ewan Klein, and Edward Lop

Python library for natural language processing.

Pricing: free — Open source, freely available · Visit website

NLTK is a leading platform for building Python programs to work with human language data. It provides easy-to-use interfaces to over 50 corpora and lexical resources, along with text processing libraries for classification, tokenization, stemming, tagging, parsing, and semantic reasoning. Suitable for linguists, engineers, students, educators, researchers, and industry users alike.

Pros

Comprehensive resource library
Extensive documentation
Active community support

Cons

Steep learning curve for beginners
Limited mobile app support

FAQ

Is NLTK free?

Yes, it's open source and freely available.

What platforms does NLTK support?

Windows, macOS, and Linux.

Does NLTK have mobile apps?

No, primarily a desktop tool.

Last updated: 2026-06-21