Dakota version 5.3, released 1/31/2013, and its partner version 5.3.1, released 5/15/2013, feature new adaptive, sparse, and surrogate-based UQ methods, new Bayesian calibration methods, and improvements to discrete optimization. The new versions also include enhancements to the testing infrastructure, core framework, and portability (including to native Windows). The Dakota user experience continues to improve through the Dakota GUI (named JAGUAR); formal release of JAGUAR version 3.0 is scheduled for June 2013. Dakota version 5.3.1 includes revamped getting-started, tutorial, and examples in the user’s manual. Version 5.3.1 is the first of Dakota’s new semiannual releases, with future deployments scheduled for May and November of each year.