The REX School/Symposium "A Decade of Concurrency - Reflections and Perspectives" was the final event of a ten-year period of cooperation between three Dutch research groups working on the foundations of concurrency.
Ever since its inception in 1983, the goal of the project has been to contribute to the cross-fertilization between formal methods from the fields of syntax, semantics, and proof theory, aimed at an improved understanding of the nature of parallel computing. The material presented in this volume was prepared by the lecturers (and their coauthors) after the meeting took place.
In total, the volume constitutes a thorough state-of-the-art report of the research activities in concurrency.

Researchers working on the semantics of programming languages came together in The Netherlands in June 1992 for a workshop on Semantics - Foundations and Applications. This volume is based on the meeting and contains material prepared by the lecturers after the meeting took place. The volume includes papers on a wide range of topics in both foundationsand applications, including: - Comparative domain theory, category theory, information systems, - Concurrency: process algebras, asynchronous communication, action semantics, trace nets, process refinement, concurrent constraint programming, - Predicate transformers, refinement, weakest preconditions, - Comparative semantics of programming concepts, full abstraction, - Reasoning about programs: total correctness, epistemic logic, - Logic programming, - Functional programming: sequentiality, integration with concurrency, applied structured operational semantics. The workshop was an activity of the project REX (Research andEducation in Concurrent Systems) sponsored by the Netherlands NFI (NationaleFaciliteit Informatica) Programme.

In the past decade, the formal theory of specification, verfication and development of real-time programs has grown from work of a few specialized groups to a real "bandwagon." Many eminent research groups have shifted their interests in this direction. Consequently, research in real-time is now entering established research areas in formal methods, such as process algebra, temporal logic, and model checking. This volume contains the proceedings of a workshop dedicated to the theory of real-time with the purpose of stepping back and viewing the results achieved as well as considering the directions of ongoing research. The volume gives a representative picture of what is going on in the field worldwide, presented by eminent, active researchers. The material in the volume was prepared by the authors after the workshop took place and reflects the results of the workshop discussions.

Over the last few years, object-oriented programming has been recognized as the best way currently available of structuring software systems. It emphasizes grouping together data and the operations performed on them, encapsulating the whole behind a clean interface, and organizing the resulting entities in a hierarchy based on specialization in functionality. In this way it provides excellent support for the construction of large systems. Up to now, there has been relatively little effort to develop formal theories of object-oriented programming. However, for the field to mature, a more formal understanding of the basic concepts of object-oriented programming is necessary. This volume presents the proceedings of the School/Workshop on Foundations of Object-Oriented Programming (FOOL) held in Noordwijkerhout, The Netherlands, May 28 - June 1, 1990. The workshop was an activity of the project REX (Research and Education in Concurrent Systems).