The seventh book in the CHDL Series is composed of a selection of the best articles from the Forum on Specification and Design Languages (FDL'04). FDL is the European Forum to learn and exchange on new trends on the application of languages and models for the design of electronic and heterogeneous systems.The forum was structured around four workshops that are all represented in the book by outstanding articles: Analog and Mixed-Signal Systems, UML-based System Specification and Design, C/C++-Based System Design and Languages for Formal Specification and Verification.The Analog and Mixed-Signal Systems contributions bring some answers to the difficult problem of co-simulating discrete and continuous models of computation. The UML-based System Specification and Design chapters bring insight into how to use the Model Driven Engineering to design Systems-on-Chip.  The C/C++-Based System Design articles mainly explore system level design with SystemC. The Languages for FormalSpecification and Verification is represented by an invited contribution on the use of temporal assertions for symbolic model checking and simulation. And finally chapter in this book contributed by preeminent members of the automotive design industry presents the recent industry standard AutoSAR.Overall this book is an excellent opportunity to catch up with the latest research developments in the field of languages for electronic and heterogeneous system design.