More links, from the WinBUGS pages.
Black Box, the compiler that OpenBUGS is written with.
JAGS, "Just Another Gibbs Sampler" by Martyn Plummer. A competitor!
Elicitor, Interactive Software for Eliciting Informative Priors for a Bayesian Logistic Regression Model.
R-MCMC project, a project trying to bring together everybody working on MCMC in R.
First Bayes A teaching programme, used to introduce Bayesian ideas.
bugs.R, Andrew Gelman's functions for running BUGS from R: this allows you to create the data, inits etc. in R, and pass them to OpenBUGS, and then the output gets past back to R for you to play around with at will.
MATBUGS, Kevin Murphy's interface of BUGS to MATLAB. Apparently this means engineers will be in our thrall too.