mBayes

mBayes lets you design Bayesian networks with an easy to use, multi-touch UI. You can add and connect nodes, and edit the conditional probability tables of your network. You can set observed values, and run 3 types of inference to compute posterior probabilities.

Great for building simple Bayesian models and gaining an intuitive understanding of probabilistic inference.

This Bayesian network app is ideal for educators and students who want to learn more about probabilistic graphical models, an important component of many machine learning and artificial intelligence systems.