The 2009 International Symposium on Rule Interchange and Applications (RuleML 2009), collocated in Las Vegas, Nevada, with the 12th International Business Rules Forum, was the premier place to meet and to exchange ideas from all ?elds of rules technologies. The aims of RuleML 2009 were both to present new and interesting research results and to show successfully deployed rule-basedapplications.This annualsymposium is the ?agshipevent of the Rule Markup and Modeling Initiative (RuleML). The RuleML Initiative (www.ruleml.org) is a non-pro't umbrella organi- tion of several technical groups...