[nl]

OpenNLP is pretty mediocre.

StanfordNLP is pretty close to the state of the art for things like POS tagging (in English anyway. Not familiar with benchmarks in other languages)

As mentioned in the other reply, Spacy, Gensim, Fasttext and VW are great for specific things.

[mtthwmtthw]

What is your criteria if you think OpenNLP is mediocre?