I don't have a JS version, but here's a functioning HMM tagger in under 300 lines of Python: http://gist.github.com/503784 http://gist.github.com/503784 (model

I don't have a JS version, but here's a functioning HMM tagger in under 300 lines of Python: http://gist.github.com/503784 http://gist.github.com/503784 (model loading doesn't work yet for some reason, but you see what it's doing in principle). This uses a smoothed trigram HMM, so it should, in principle, be a bit better than NLTK's HMM tagger but not as good as serious POS tagging packages (e.g. hunpos, or the Stanford POS tagger)