If you are a Python person (very popular language in the data sciences realm these days). Your gateway drug to linguistic and textual analysis is going to be NLTK.
The free book and tutorials are great and you can get up and running pretty quickly.
NLTK's lower learning curve is great for getting your head around NLP concepts. Once you start looking for increased function or performance... you'll find yourself graduating to a SciKit-Learn (http://scikit-learn.org/stable/).
In the Java world... I think Mahout is/was popular. Quite a bit more setup to get through in order get this up and running.