Grok is a library of Java components for performing various natural language tasks. These include several preprocessing tasks, chart parsing, a large categorial grammar for English (induced from the Penn treebank), and some knowledge representation components (basic coreference, salience tracking, etc.). The library also has a companion kit which provides a GUI interface to the components, several of which are implementations of interfaces in the Quipu OpenNLP API.
Maximum entropy is a powerful method for constructing statistical models of classification tasks, such as part-of-speech tagging in Natural Language Processing. The Quipu Maximum Entropy Package is a Java implementation of the maximum entropy framework. It allows you to train, evaluate, and use maxent models.