Try this one
https://github.com/louismullie/stanford-core-nlp
About stanford-core-nlp gem
This gem provides high-level Ruby bindings to the Stanford Core NLP package, a set natural language processing tools for tokenization, sentence segmentation, part-of-speech tagging, lemmatization, and parsing of English, French and German. The package also provides named entity recognition and coreference resolution for English.
http://nlp.stanford.edu/software/corenlp.shtml
demo page
http://nlp.stanford.edu:8080/corenlp/
