The 2009 Edsger W. Dijkstra Prize in Distributed Computing -- The 2009 Edsger W. Dijkstra Prize in Distributed Computing -- Michel Raynal and Shmuel Zaks 60th Birthday Symposium -- Computing, Observing, Controlling, Checkpointing: Symbiosis Is Even Better Than Agreement! -- What Agreement Problems Owe Michel -- Shmuel Zaks - The Early Years: A Combinatorialist in Distributed Computing -- Shmuel Zaks - The Mathematician, Computer Scientist and Personality -- Award Nominees (Session 2B) -- The Disagreement Power of an Adversary -- New Bounds for the Controller Problem -- On Set Consensus Numbers -- The Abstract MAC Layer -- Randomization Can Be a Healer: Consensus with Dynamic Omission Failures -- Transactional Memory (Session 1A) -- Interrupting Snapshots and the Java Size() Method -- Elastic Transactions -- Brief Announcement: Transactional Scheduling for Read-Dominated Workloads -- Shared Memory (Session 1B) -- Tight Group Renaming on Groups of Size g Is Equivalent to g-Consensus -- The RedBlue Adaptive Universal Constructions -- Help When Needed, But No More: Efficient Read/Write Partial Snapshot -- Contention-Sensitive Data Structures and Algorithms -- Brief Announcement: Acceleration by Contention for Shared Memory Mutual Exclusion Algorithms -- Brief Announcement: Incremental Component-Based Modeling, Verification, and Performance Evaluation of Distributed Reset -- Distributed and Local Graph Algorithms (Session 1C) -- Local Computation of Nearly Additive Spanners -- A Local 2-Approximation Algorithm for the Vertex Cover Problem -- Distributed Discovery of Large Near-Cliques -- Distributed Fractional Packing and Maximum Weighted b-Matching via Tail-Recursive Duality -- Brief Announcement: Decidable Graph Languages by Mediated Population Protocols -- Brief Announcement: Towards Secured Distributed Polling in Social Networks -- Modeling Issues (Session 1D) -- What Can Be Observed Locally? -- At-Most-Once Semantics in Asynchronous Shared Memory -- Nonblocking Algorithms and Backward Simulation -- Brief Announcement: Efficient Model Checking of Fault-Tolerant Distributed Protocols Using Symmetry Reduction -- Brief Announcement: Dynamic FTSS in Asynchronous Systems: The Case of Unison -- Game Theory (Session 2A) -- Dynamics in Network Interaction Games -- Brief Announcement: Cloud Computing Games: Pricing Services of Large Data Centers -- Failure Detectors (Session 2C) -- On the Existence of Weakest Failure Detectors for Mutual Exclusion and k-Exclusion -- Crash-Quiescent Failure Detection -- The Price of Anonymity: Optimal Consensus Despite Asynchrony, Crash and Anonymity -- Brief Announcement: On Implementing Omega Efficiently in the Crash-Recovery Model -- Brief Announcement: The Minimum Failure Detector for Non-Local Tasks in Message-Passing Systems -- Brief Announcement: Weak Synchrony Models and Failure Detectors for Message Passing (k-)Set Agreement -- From Theory to Practice (Session 3A) -- Brief Announcement Zab: A Practical Totally Ordered Broadcast Protocol -- Graph Algorithms and Routing (Session 3B) -- Compact Multicast Routing -- Compact Routing in Power-Law Graphs -- Virtual Ring Routing Trends -- A New Self-stabilizing Minimum Spanning Tree Construction with Loop-Free Property -- Euler Tour Lock-In Problem in the Rotor-Router Model -- Consensus and Byzantine Agreement (Session 3C) -- Optimum Simultaneous Consensus for General Omissions Is Equivalent to an NP Oracle -- On the Number of Synchronous Rounds Sufficient for Authenticated Byzantine Agreement -- From Almost Everywhere to Everywhere: Byzantine Agreement with Bits -- Brief Announcement: A Leader-free ByzantineConsensus Algorithm -- Radio Networks (Session 3D) -- Efficient k-Shot Broadcasting in Radio Networks -- Keeping Mobile Robot Swarms Connected -- Consensus and Mutual Exclusion in a Multiple Access Channel -- Brief Announcement: Efficient Utilization of Multiple Interfaces in Wireless Ad Hoc Networks -- Brief Announcement: The Speed of Broadcasting in Random Networks - Density Does Not Matter.

This book constitutes the refereed proceedings of the 23nd International Symposium on Distributed Computing, DISC 2009, held in Elche, Spain, in September 2009. The 33 revised full papers, selected from 121 submissions, are presented together with 15 brief announcements of ongoing works; all of them were carefully reviewed and selected for inclusion in the book. The papers address all aspects of distributed computing, and were organized in topical sections on Michel Raynal and Shmuel Zaks 60th birthday symposium, award nominees, transactional memory, shared memory, distributed and local graph algorithms, modeling issues, game theory, failure detectors, from theory to practice, graph algorithms and routing, consensus and byzantine agreement and radio networks.