This book constitutes the thoroughly refereed post-workshop proceedings of the 4th International Workshop on Communication, Architecture, and Applications for Network-Based Parallel Computing, CANPC 2000, held in Tolouse, France in January 2000. The 12 revised full papers presented were carefully reviewed and selected for inclusion in the book. The papers are organized in sections on program development and execution support, network router architecture, system support for communication abstractions, and network software and interface architecture.

Program Development and Execution Support.- REXEC: A Decentralized, Secure Remote Execution Environment for Clusters.- A Visual BSP Programming Environment for Distributed Computing.- Transparent Network Connectivity in Dynamic Cluster Environments.- Network Router Architecture.- A New Methodology to Compute Deadlock-Free Routing Tables for Irregular Networks.- On the Performance of Up*/Down* Routing.- Extending Dynamic Reconfiguration to NOWs with Adaptive Routing.- System Support for Communication Abstractions.- MPI Derived Data Types Support in VIRTUS.- Fast Collective Communication Algorithms for Reflective Memory Network Clusters.- Broadcast/Multicast over Myrinet Using NIC-Assisted Multidestination Messages.- Network Software and Interface Architecture.- Simulation Studies of Gigabit Ethernet Versus Myrinet Using Real Application Cores.- Comparison and Evaluation of Design Choices for Implementing the Virtual Interface Architecture (VIA).- Efficient Communication Using Message Prediction for Cluster of Multiprocessors.