In natural language understanding, there is a hierarchy of lenses through which we can extract meaning - from words to sentences to paragraphs to documents. At the document level, one of the most useful ways to understand text is by analyzing its topics.
Stan modeling language and C++ library for Bayesian inference. NUTS adaptive HMC (MCMC) sampling, automatic differentiation, R, shell interfaces. Gelman.
A. Bakalov, A. McCallum, H. Wallach, and D. Mimno. Proceedings of the 12th ACM/IEEE-CS Joint Conference on Digital Libraries, page 237--240. New York, NY, USA, ACM, (2012)