The paper discusses the development of the OxCal radiocarbon calibration program. Key developments include improved algorithms for handling multiple phases, enhanced sampling algorithms for better Bayesian analysis convergence, and more comprehensive reporting of convergence. The calibration algorithms have been refined to better account for error terms and variability in calibration curves, particularly with the INTCAL98 curve. Mixed calibration curves are now supported, allowing for the combination of marine and terrestrial sources or geological age carbon. The program also includes methods for grouping events into coherent sequences using boundaries, which helps in modeling the distribution of dates more accurately. The Markov Chain Monte Carlo (MCMC) sampling has been improved, incorporating both Gibbs and Metropolis-Hastings algorithms for faster convergence. Additional tools have been provided to monitor and ensure convergence. The program has been tested with simulated dating scenarios and effective prior analysis to validate its performance. Overall, OxCal has evolved to handle complex models more effectively, with a focus on improving accuracy and reliability in radiocarbon dating.The paper discusses the development of the OxCal radiocarbon calibration program. Key developments include improved algorithms for handling multiple phases, enhanced sampling algorithms for better Bayesian analysis convergence, and more comprehensive reporting of convergence. The calibration algorithms have been refined to better account for error terms and variability in calibration curves, particularly with the INTCAL98 curve. Mixed calibration curves are now supported, allowing for the combination of marine and terrestrial sources or geological age carbon. The program also includes methods for grouping events into coherent sequences using boundaries, which helps in modeling the distribution of dates more accurately. The Markov Chain Monte Carlo (MCMC) sampling has been improved, incorporating both Gibbs and Metropolis-Hastings algorithms for faster convergence. Additional tools have been provided to monitor and ensure convergence. The program has been tested with simulated dating scenarios and effective prior analysis to validate its performance. Overall, OxCal has evolved to handle complex models more effectively, with a focus on improving accuracy and reliability in radiocarbon dating.