Invited Talk -- Playing with Rules -- Invited Papers -- The Refinement of Choreographed Multi-Agent Systems -- Goal Generation from Possibilistic Beliefs Based on Trust and Distrust -- Monitoring Directed Obligations with Flexible Deadlines: A Rule-Based Approach -- Contributed Papers -- Unifying the Intentional and Institutional Semantics of Speech Acts -- Tableaux for Acceptance Logic -- Ontology and Time Evolution of Obligations and Prohibitions Using Semantic Web Technology -- Prioritized Goals and Subgoals in a Logical Account of Goal Change - A Preliminary Report -- Declarative and Numerical Analysis of Edge Creation Process in Trust-Based Social Networks -- Computing Utility from Weighted Description Logic Preference Formulas -- Explaining and Predicting the Behavior of BDI-Based Agents in Role-Playing Games -- Correctness Properties for Multiagent Systems -- Reasoning and Planning with Cooperative Actions for Multiagents Using Answer Set Programming -- Social Commitments in Time: Satisfied or Compensated -- Verifying Dribble Agents.

This book constitutes the thoroughly refereed post-workshop proceedings of the 7th International Workshop on Declarative Agent Languages and Technologies, DALT 2009, held in Budapest, Hungary, on May 11, 2009, as a satellite workshop of the 8th International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS 2009. The 11 revised full papers presented together with 1 invited lecture and 3 invited papers from the AAMAS main conference - substantially enhanced after the workshop - were carefully selected from 17 initial submissions. The papers combine declarative and formal approaches with engineering and technology aspects of agents and multiagent systems and focus especially on areas such as the semantic web, service-oriented computing, web services, security, and electronic contracting.