The1stEuropeanWorkshoponSoftwareArchitecture(EWSA2004)washeldin St Andrews, Scotland on 21-22 May 2004. The workshop provided an inter- tional forum for researchers and practitioners from academia and industry to discuss a wide range of topics in the area of software architecture and to jointly formulate an agenda for future research. We were pleased to continue this forum in EWSA 2005. The importance of software architecture as a fundamental area of software engineeringcontinues togrow.Inaddition todescribingtheunderlyingstructure of software systems, architectures are now being used to model and understand dynamicbehavior.Newareasofstudy, whichhavetheirrootsincontrolsystems, arebeginningtoemerge.The?eldofautonomicsrequiresanunderlyingsoftware architecture to describe the executing computation as does any control system that involves system evolution. The range of papers in EWSA 2005 re?ected both the traditional and new applications of software architecture techniques. EWSA 2005 distinguished between three types of papers: research papers (which describe authors' novel research work), a case study (which describes experiencesrelatedtosoftwarearchitectures)andpositionpapers(whichpresent concise arguments about a topic of software architecture research or practice). TheProgrammeCommitteeselected18papers(12researchpapers,4position papers, 1 case study, and 1 unrefereed invited paper) out of 41 submissions from 20 countries (Australia, Belgium, Brazil, Chile, China, Czech Republic, Finland, France, Germany, India, Italy, Ireland, Korea, Netherlands, Pakistan, Portugal, Spain, Switzerland, UK, USA). All submissions were reviewed by at least three members of the Programme Committee. Papers were selected based on originality, quality, soundness and relevance to the workshop. Credit for the quality of the proceedings goes to all authors of papers.

The last decade has been one of great progress in the field of software architecture research and practice. Software architecture has emerged as an important subdis- pline of software engineering. A key aspect of the design of any software system is its architecture, i. e. the fundamental organization of a system embodied in its com- nents, their relationships to each other, and to the environment, and the principles guiding its design and evolution (as defined in the Recommended Practice for Arc- tectural Description of Software-Intensive Systems -- IEEE Std 1471-2000). - The First European Workshop on Software Architecture (EWSA 2004) provided an international forum for researchers and practitioners from academia and industry to discuss a wide range of topics in the area of software architecture, and to jointly f- mulate an agenda for future research in this field. EWSA 2004 distinguished among three types of papers: research papers (which describe authors novel research work), experience papers (which describe real-world experiences related to software architectures), and position papers (which present concise arguments about a topic of software architecture research or practice). The Program Committee selected 19 papers (9 research papers, 4 experience - pers, and 6 position papers) out of 48 submissions from 16 countries (Australia, B- zil, Canada, Chile, Finland, France, Germany, Italy, Japan, Korea, The Netherlands, Spain, Switzerland, Turkey, UK, USA). All submissions were reviewed by three members of the Program Committee."

The Fifth International Workshop on Persistent Object Systems took place in the historic setting of Centro Studi "I Cappuccini" della Cassa di Risparmio di San Miniato. San Miniato (pisa). Italy from 1-4 September 1992. The workshop continued the tradition of the previous four in concentrating on the design. implementation and use of persistent systems. The other workshops in the series are: Venue Date Organisers Appin POSI 27-30 August Atkinson. Buneman 1985 Scotland and Morrison Appin POS2 25-28 August Atkinson and Morrison 1987 Scotland Newcastle POS3 10-13 January Koch and Rosenberg 1989 Australia POS4 23-27 September Marthas Vineyard DearIe. Mitchell 1990 USA andZdonik The series of Workshops on Database Programming Languages is closely related to the POS workshops. These have been held every other year out of phase with POS. and tend to concentrate on the design and theory of persistent systems. The workshops in the DBPL series are: Date Venue Organisers DBPL 1 7-10 September Roscoff Bancilhon and France 1987 Buneman DBPL2 4-8 June Salishan Hull. Morrison and 1989 USA Stemple 27-30 August Nafplion Kanellakis and DBPL3 Greece Schmidt 1991 Preface vi This book follows the format of the workshop. Of the 39 papers submitted for the workshop, 22 were accepted in order to allow plenty of time for discussion. As at POS 4 in Marthas Vineyard each paper was followed by 5 minutes of questions and each session by a 30 minute discussion.