Following the successful workshops held in St. Andrews, Scotland, UK in 2004 (EWSA 2004, Springer LNCS 3527) and in Pisa, Italy in 2005 (EWSA 2005, Springer LNCS 3047), the 3rd European Workshop on Software Architecture (EWSA 2006) held in Nantes, France during September 4-5, 2006 provided an internationalforumforresearchersandpractitionersfromacademiaandindustry to present innovative research and discuss a wide range of topics in the area of software architecture. Software architecture has emerged as an important subdiscipline of software engineering encompassing a broad set of languages, styles, models, tools, and processes. The role of software architecture in the engineering of softwa- intensive systems has become more and more important and widespread. Ch- lenging applications include support for dynamic, adaptive, autonomic and mobile systems. The workshopfocused onformalisms,technologies,and processesfor descr- ing, verifying, validating, re?ning, building, and evolving software systems, in particular based on component and service-oriented architectures. Topics c- eredincluded architecturemodeling,architecturalaspects,architectureanalysis, transformation and synthesis, quality attributes, model-driven engineering, and architecture-based support for assembling components and developing com- nent and service-oriented systems. EWSA 2006, distinguished between two types of papers: research papers, which describe authors novel research work, and position papers, which present concise arguments about a topic of software architecture research or practice.