This book constitutes the refereed proceedings of the international Joint Modular Languages Conference, JMLC 2006. The 23 revised full papers presented together with 2 invited lectures were carefully reviewed and selected from 36 submissions. The papers are organized in topical sections on languages, implementation and linking, formal and modelling, concurrency, components, performance, and case studies.

Separating Concerns with Domain Specific Languages.- Event-Based Programming Without Inversion of Control.- Programming Language Concepts for Multimedia Application Development.- Implicit and Dynamic Parameters in C++.- Reconciling Virtual Classes with Genericity.- Oberon Script: A Lightweight Compiler and Runtime System for the Web.- Efficient Layer Activation for Switching Context-Dependent Behavior.- Object-Oriented Language Processing.- A Framework for Modular Linking in OO Languages.- Flexible Type-Safe Linking of Components for Java-Like Languages.- Towards a Formal Semantics for AspectJ Weaving.- Symbolic Analysis of Imperative Programming Languages.- Array-Structured Object Types for Mathematical Programming.- MetaModelica: A Unified Equation-Based Semantical and Mathematical Modeling Language.- A Component Language for Structured Parallel Programming.- Internal and External Token-Based Synchronization in Object-Oriented Languages.- A New Component-Oriented Programming Language with the First-Class Connector.- A Component Plug-In Architecture for the .NET Platform.- Improve Component-Based Programs with Connectors.- Automatic Object Colocation Based on Read Barriers.- Nearly Optimal Register Allocation with PBQP.- Fast Profile-Based Partial Redundancy Elimination.- The Dining Philosophers Problem Revisited.- A Mobile Agent Service-Oriented Scripting Language Encoded on a Process Calculus.- A Case Study in Concurrent Programming with Active Objects.