From the webpage:
“Natural” is a general natural language facility for nodejs. Tokenizing, stemming, classification, phonetics, tf-idf, WordNet, and some inflection are currently supported.
It’s still in the early stages, and am very interested in bug reports, contributions and the like.
Note that many algorithms from Rob Ellis’s node-nltools are being merged in to this project and will be maintained here going forward.
At the moment most algorithms are English-specific but long-term some diversity is in order.
Aside from this README the only current documentation is here on my blog.
Just in case you are looking for natural language processing capabilities with nodejs.