Peer-to-Peer Computing -- Approximate Object Location and Spam Filtering on Peer-to-Peer Systems -- Efficient Peer-to-Peer Keyword Searching -- NaradaBrokering: A Distributed Middleware Framework and Architecture for Enabling Durable Peer-to-Peer Grids -- Publish-Subscribe Middleware I -- A Framework for Event Composition in Distributed Systems -- Content Distribution for Publish/Subscribe Services -- Supporting Mobility in Content-Based Publish/Subscribe Middleware -- Adaptability and Context-Awareness -- Fine-Grained Dynamic Adaptation of Distributed Components -- A Middleware for Context-Aware Agents in Ubiquitous Computing Environments -- Adaptable Architectural Middleware for Programming-in-the-Small-and-Many -- Publish-Subscribe Middleware II -- Opportunistic Channels: Mobility-Aware Event Delivery -- Congestion Control in a Reliable Scalable Message-Oriented Middleware -- On Shouting “Fire!”: Regulating Decoupled Communication in Distributed Systems -- Web-Base Middleware -- Performance Comparison of Middleware Architectures for Generating Dynamic Web Content -- Prefetching Based on Web Usage Mining -- Distributed Versioning: Consistent Replication for Scaling Back-End Databases of Dynamic ContentWeb Sites -- Component-Based Middleware -- Abstraction of Transaction Demarcation in Component-Oriented Platforms -- Optimising Java RMI Programs by Communication Restructuring -- The JBoss Extensible Server -- Next Generation Middleware -- Flexible and Adaptive QoS Control for Distributed Real-Time and Embedded Middleware -- Large-Scale Service Overlay Networking with Distance-Based Clustering -- A Step Towards a New Generation of Group Communication Systems -- Mobile and Ubiquitos Computing -- A Middleware-Based Application Framework for Active Space Applications -- A Proactive Middleware Platform for Mobile Computing -- A Flexible Middleware System for Wireless Sensor Networks -- Middleware Service for Mobile Ad Hoc Data Sharing, Enhancing Data Availability.

Next-generation distributed applications and systems are increasingly developed using middleware. This dependency poses hard R&D challenges, including - tency hiding, masking partial failure, information assurance and security, legacy integration, dynamic service partitioning and load balancing, and end-to-end quality of service speci?cation and enforcement. To address these challenges, researchers and practitioners must discover and validate techniques, patterns, and optimizations for middleware frameworks, multi-level distributed resource management, and adaptive and re?ective middleware architectures. Following the success of the past IFIP/ACM Middleware conferences (Lake District/UK, Palisades/USA, and Heidelberg/Germany) and building upon the success of past USENIX COOTS conferences, the Middleware 2003 conference is the premier international event for middleware research and technology. The scope of the conference is the design, implementation, deployment, and eval- tion of distributed system platforms, architectures, and applications for future computing and communication environments. This year, we had a record of 158 submissions, among which the top 25 - pers were selected for inclusion in the technical program of the conference. All papers were evaluated by at least three reviewers with respect to their origin- ity,technicalmerit,presentationquality,andrelevancetotheconferencethemes. The selected papers present the latest results and breakthroughs on middleware research in areas including peer-to-peer computing, publish-subscriber archit- tures, component- and Web-based middleware, mobile systems, and adaptive computing.