Stan is absolutely a world class general Bayesian sampling tool. It replaces things like BUGS and uses fantastic algorithms for fast convergence. One of the maj

Stan is absolutely a world class general Bayesian sampling tool. It replaces things like BUGS and uses fantastic algorithms for fast convergence. One of the major people behind it, Andrew Gelman, is a leader in applied hierarchical modeling and uses it to great effect in social sciences. If you have even vague interest in applied statistics in fields with lesser ability to design experimental controls then you should investigate this tool.