IWAN 2004 -- GateScript: A Scripting Language for Generic Active Gateways -- Management and Performance of Virtual and Execution Environments in FAIN -- Secure, Customizable, Many-to-One Communication -- Distributed Instrusion Prevention in Active and Extensible Networks -- Secure Service Signaling and Fast Authorization in Programmable Networks -- Invited Papers -- Tackling the Complexity of Future Networks -- Evaluation of Integration Effect of Content Location and Request Routing in Content Distribution Networks -- Building a Reliable Multicast Service Based on Composite Protocols for Active Networks -- Network Programmability for VPN Overlay Construction and Bandwidth Management -- A Framework for Developing Mobile Network Services -- Using Active Networking’s Adaptability in Ad Hoc Routing -- Active Networking for TCP over Wireless -- A Detection and Filter System for Use Against Large-Scale DDoS Attacks in the Internet Backbone -- Dynamic Link Measurements Using Active Components -- Simple Active Mechanisms for Measuring and Monitoring Service Level Topologies.