This book constitutes the refereed proceedings of the 12th European Conference on Object-Oriented Programming, ECOOP'98, held in Brussels, Belgium, in July 1998. The book presents 24 revised full technical papers selected for inclusion from a total of 124 submissions; also presented are two invited papers. The papers are organized in topical sections on modelling ideas and experiences; design patterns and frameworks; language problems and solutions; distributed memory systems; reuse, adaption and hardware support; reflection; extensible objects and types; and mixins, inheritance and type analysis complexity.

At the time of writing (mid-October 1998) we can look back at what has been a very successful ECOOP’98. Despite the time of the year – in the middle of what is traditionally regarded as a holiday period – ECOOP'98 was a record breaker in terms of number of participants. Over 700 persons found their way to the campus of the Brussels Free University to participate in a wide range of activities. This 3rd ECOOP workshop reader reports on many of these activities. It contains a careful selection of the input and a cautious summary of the outcome for the numerous discussions that happened during the workshops, demonstrations and posters. As such, this book serves as an excellent snapshot of the state of the art in the field of object oriented programming. About the diversity of the submissions A workshop reader is, by its very nature, quite diverse in the topics covered as well as in the form of its contributions. This reader is not an exception to this rule: as editors we have given the respective organizers much freedom in their choice of presentation because we feel form follows content. This explains the diversity in the types of reports as well as in their lay out.

Following a 13-year tradition of excellence, the 14th ECOOP conference repeated the success of its predecessors. This excellence is certainly due to the level of maturity that object-oriented technology has reached, which warrants its use as a key paradigm in any computerized system. The principles of the object-oriented paradigm and the features of systems, languages, tools, and methodologies based on it are a source of research ideas and solutions to many in all areas of computer science. ECOOP 2000 showed a thriving eld characterized by success on the practical side and at the same time by continuous scienti c growth. Firmly established as a leading forum in the object-oriented arena, ECOOP 2000 received 109 high quality submissions. After a thorough review process, the program committee selected 20 papers, which well re?ect relevant trends in object-oriented research: object modeling, type theory, distribution and coo- ration, advanced tools, programming languages. The program committee, c- sisting of 31 distinguished researchers in object-orientation, met in Milan, Italy, to select the papers for inclusion in the technical program of the conference.

\My tailor is Object-Oriented". Most software systems that have been built - cently are claimed to be Object-Oriented. Even older software systems that are still in commercial use have been upgraded with some OO ?avors. The range of areas where OO can be viewed as a \must-have" feature seems to be as large as the number of elds in computer science. If we stick to one of the original views of OO, that is, to create cost-e ective software solutions through modeling ph- ical abstractions, the application of OO to any eld of computer science does indeed make sense. There are OO programming languages, OO operating s- tems, OO databases, OO speci cations, OO methodologies, etc. So what does a conference on Object-Oriented Programming really mean? I honestly don’t know. What I do know is that, since its creation in 1987, ECOOP has been attracting a large number of contributions, and ECOOP conferences have ended up with high-quality technical programs, featuring interesting mixtures of theory and practice. Among the 183 initial submissions to ECOOP’99, 20 papers were selected for inclusion in the technical program of the conference. Every paper was reviewed by three to ve referees. The selection of papers was carried out during a t- day program committee meeting at the Swiss Federal Institute of Technology in Lausanne. Papers were judged according to their originality, presentation qu- ity, and relevance to the conference topics.

This book constitutes the refereed proceedings of the 15th European Conference on Object-Oriented Programming, ECOOP 2001, held in Budapest, Hungary, in June 2001. The 18 revised full papers presented together with one invited paper were carefully reviewed and selected from 108 submissions. The book is organized in topical sections on sharing and encapsulation, type inference and static analysis, language design, implementation techniques, reflection and concurrency, and testing and design.

The refereed proceedings of the 17th European Conference on Object-Oriented Programming, ECOOP 2003, held in Darmstadt, Germany in July 2003. The 18 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 88 submissions. The papers are organized in topical sections on aspects and components; patterns, architecture, and collaboration; types; modeling; algorithms, optimization, and runtimes; and formal techniques and methodology.