OpenBUGS is a software application for the Bayesian analysis of complex statistical models using Markov chain Monte Carlo (MCMC) methods.

Versions from v3.0.7 onwards have been designed to be at least as efficient and reliable as WinBUGS over a range of test applications.

Installation problems, development and usage questions are discussed at the OpenBUGS Bulletin Board.

Attempts to port OpenBUGS to Java with the Gardens Point Component Pascal were given up in favor of a new portable implementation called JAGS.

It is parsed by OpenBUGS, which then creates an executable (compiled code) that generates a sample from the posterior distribution when run.