The purpose of the seminar was to bring together scientists working in the field of object-oriented software development. This includes object-oriented requirements analysis, specification and design, programming, testing and maintenance. The topics ranged from theoretical foundations to practical development projects.

In the paradigm of object-orientation, software systems are considered to be dynamic collections of autonomous objects that interact with each other. Autonomy means that each object encapsulates all features needed to act as an independent computing agent: individual attributes (data), methods (operations), behavior (process), and communication facilities. And each object has a unique identity that is immutable throughout its lifetime. Coincidentally, object-orientation comes with an elaborate system of types and classes, facilitating structuring and reuse of software.

The object paradigm is widely discussed in software technology, there are objectoriented programming languages, database systems, and software development methods. The basic idea is not new, essential concepts were already present in the programming language Simula, in the end sixties. Wider acceptance, however, only came with Smalltalk in the beginning eighties. But still, in many application areas, object-oriented methods and systems are not state of the art yet.

While the object paradigm is fairly successful in practice, it finds more scepticism than enthusiasm among theoreticians. But there is growing interest in clean concepts and reliable foundations. In fact, object-orientation badly needs theoretical underpinning, for improving practice and facilitating teaching.

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The seminar organizers came from three continents: Europe, Asia and America. This indicates another purpose of the seminar, namely to bring together scientists who do not meet easily because they work in distant parts of the world.

27 participants accepted the invitation and came to the seminar, among them scientists from China and Japan, the US, and several European countries.
The seminar program covered four days, from Monday to Thursday. Each morning had two talk sessions. Each afternoon except Wednesday had another talk session followed by a working group session. On Wednesday afternoon, there was the obligatory excursion.

Three working groups were set up, one on requirements engineering, one on concurrency, and one on object-oriented models, formalisms and methods for component software design. The first two working groups were organized and chaired by Roel Wieringa and Barbara Paech, respectively. The third working group was coorganized and cochaired by Yulin Feng and Zhenyu Qian. Participation was well balanced among the working groups, and discussion was lively. The findings of the working groups were presented and discussed in a plenary session. the chairpersons prepared summaries that are included in this report.

The talks showed a broad spectrum of topics around object-orientation and software, from requirements engineering via modelling, specification and design towards programming and testing. Interest is shifting towards distributed systems, bringing concurrency and communication problems into focus. Evidently, object-oriented concepts and methods are fruitfully applied to a variety of areas. Although there is still a way to go, confusion about fundamental concepts and notions is diminishing and mutual understanding is growing, due after all to a growing body of object theory.

There was beautiful weather during the seminar week, quite unusual for that time of the year. The workshop atmosphere was favorably influenced by much sun and warmth, and the excursion on Wednesday afternoon was a highly welcomed opportunity to enjoy a foretaste of summer.