Thisbook brings together a selection of the best papers from the eighteenth editionof the Forum on specification and Design Languages Conference (FDL), which tookplace on September 14-16, 2015, in Barcelona, Spain.  FDL is a well-established international forumdevoted to dissemination of research results, practical experiences and newideas in the application of specification, design and verification languages tothe design, modeling and verification of integrated circuits, complexhardware/software embedded systems, and mixed-technology systems.