Agent Architectures -- The ARTS Real-Time Agent Architecture -- Reducing Agent Plans to Workflows -- Agent Programming Languages and Methodologies -- Externalisation and Internalization: A New Perspective on Agent Modularisation in Multi-Agent System Programming -- Temporal Planning in Dynamic Environments for P-CLAIM Agents -- Data Driven Language for Agents Secure Interaction -- Programming Social Middleware through Social Interaction Types -- Social Interaction Models -- Detecting Exceptions in Commitment Protocols: Discovering Hidden States -- Verifiable Semantic Model for Agent Interactions Using Social Commitments -- Development Tools for Multi-agent Systems -- Call Graph Profiling for Multi Agent Systems -- Applications -- A Methodology for Developing Self-explaining Agents for Virtual Training.

This book constitutes the thoroughly refereed post-workshop proceedings of the Second International Workshop on Languages, Methodologies, and Development Tools for Multi-Agent Systems, LADS 2009, held in Torino, Italy, in September 2009 - as part of MALLOW 2009, a federation of workshops on Multi-Agent Logics, Languages, and Organizations. The 10 revised full papers presented were carefully selected during two rounds of reviewing and improvement from 14 initial submissions. The papers are organized in topical sections on agent architectures, agent programming languages and methodologies, social interaction models, development tools for multi-agent systems, and applications.