JAGS is Just Another Gibbs Sampler -- a program for analysis of
Bayesian hierarchical models using Markov Chain Monte Carlo (MCMC)
simulation.

The functionality of JAGS is based on the BUGS program created by the
MRC Biostatistics Unit (http://www.mrc-bsu.cam.ac.uk/). There is a short
manual that describes the differences between JAGS and BUGS.

Some of the BUGS examples have been modified to run with JAGS, and have
been turned into a test suite.

WWW: http://mcmc-jags.sourceforge.net/