This book constitutes the refereed proceedings of the International RuleML Symposium on Rule Interchange and Applications, RuleML 2007, held in Orlando, Florida, October 2007.The nine revised full papers presented together with two invited papers, nine short papers and three demo papers were carefully reviewed and selected from 41 submissions. The papers are organized in topical sections on Business Process, Policy and IT Service Management and Modeling, Rule Languages and Interchange Standards, Business Rules, Rule Engines and Applications, RuleML-2007 Challenge, Rules, Reasoning, and Ontologies and Reaction Rules and Rule Applications.