The Apache OpenNLP library is a machine learning based toolkit for the processing of natural language text. It supports the most common NLP tasks, such as tokenization, sentence segmentation, part-of-speech tagging, named entity extraction, chunking, parsing, and coreference resolution.
StanfordNLP is an algorithms that allow computers to process and understand human languages.It covers areas such as sentence understanding, machine translation, probabilistic parsing and tagging, biomedical information extraction, grammar induction, word sense disambiguation, automatic question answering, and text to 3D scene generation.
LingPipe works by using computational linguistics for processing text. LingPipe has a wide range of usability in finding the names of people, organizations or locations in news. It can also be used to classify Twitter search results into categories. Suggest correct spellings of queries etc.
GATE is open source software capable of solving almost any text processing problem it yields a wide range of application in processing voice of the customer, cancer research, drug research, decision support, recruitment, web mining, information extraction, semantic annotation etc
NLTK is one of the leading platform used by Python programs to work with human language. The main features of NLTK is that it provides easy-to-use interfaces, it has text processing libraries for classification, tokenization, stemming, tagging, parsing, and semantic reasoning, and an active discussion forum