OpenNLP

Apache OpenNLP, maintained by the Apache Software Foundation, is a machine-learning-based toolkit for natural language processing, handling sentence segmentation, tokenization, part-of-speech tagging, named entity extraction, parsing, coreference resolution, and language detection. It ships pre-trained models ready to use out of the box, integrates via Maven or Gradle into Java-based projects, and covers tasks ranging from basic text segmentation to more advanced parsing and coreference resolution. As an official Apache project, it has documented releases, active community mailing lists, and an issue tracker. Completely free and open source under the Apache License 2.0. Good fit for a Java developer who needs core NLP building blocks (tokenization, NER, POS tagging) integrated directly into a JVM-based application, rather than calling out to an external NLP service.