|Original author(s)||Andrew Thomas|
|Stable release||v3.2.2 / April 30, 2013|
|Written in||Component Pascal|
|Operating system||Windows, Unix/Linux & Mac OS (using Wine)|
|Platform||Intel x86 - 32-bit|
|License||GNU General Public License|
OpenBUGS is a computer software for the Bayesian analysis of complex statistical models using Markov chain Monte Carlo (MCMC) methods. OpenBUGS is the open source variant of WinBUGS (Bayesian inference Using Gibbs Sampling). It runs under Windows and Linux, as well as from inside the R statistical package. 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.
Differences from WinBUGS 
In addition to the different licence and greater range of operating systems, a fundamental difference between OpenBUGS and WinBUGS is the way in which the expert system selects the updating algorithm to use for the class of full conditional distribution of each node. While WinBUGS defines one algorithm for each possible class, there is no limit to the number of algorithms that OpenBUGS can use, allowing greater flexibility and extensibility. The user can select the updater to be used for each node after compilation. Further differences are detailed on the OpenBUGS website.
Programming language 
The source code of OpenBUGS is written in the Component Pascal programming language and is dependent on the Component Pascal libraries provided by Oberon Microsystems as part of the Blackbox Component Framework. The development tools are available as open source. The compilation of OpenBUGS is straightforward for Windows, but less well documented for Linux. Installation problems, development and usage questions are discussed at the OpenBUGS Bulletin Board.
The BUGS language is the language that specifies the model code. It is parsed by OpenBUGS, which then creates an executable (compiled code) that generates a sample from the posterior distribution when run.
OpenBUGS was designed to run together with S-Plus and the BUGS language is similar to the S programming language. OpenBUGS works well together with R; the BRugs module provides some interoperability, and R modules help further analyses.
- Thomas, Neal (2010-01-20). "Overview". OpenBUGS website. Retrieved 9 October 2010.
- Lunn, D.; Spiegelhalter, D.; Thomas, A.; Best, N. (2009). "The BUGS project: Evolution, critique and future directions". Statistics in Medicine 28: 3049–3067. doi:10.1002/sim.3680. PMID 19630097.
- Thomas, Neal (2010-10-05). "Changes Between WinBUGS and OpenBUGS". OpenBUGS website. Retrieved 9 October 2010.
- BUGS 0.5 Manual, date 1996-08-14
- OpenBUGS Official website