This volume contains selected papers of the International Workshop on "Categorical Methods in Computer Science - with Aspects from Topology" and of the "6th International Data Type Workshop" held in August/September 1988 in Berlin. The 23 papers of this volume are grouped into three parts: "Part " "1" includes papers on categorical foundations and fundamental concepts from category theory in computer science. "Part 2" presents applications of categorical methods to algebraic specification languages and techniques, data types, data bases, programming, and process specifications. "Part 3" comprises papers on categorial aspects from topology which mainly concentrate on special adjoint situations like cartesian closeness, Galois connections, reflections, and coreflections which are of growing interest in categorical topology and computer science.

This volume contains the major part of the contributions to the 3rd Workshop on Theory and Appl ications of Abstract Data Types held in Bremen (Germany) from November 13 to November 16, 1984. The workshop, as both its predecessors (Sorpesee, 1982 and Passau, 1983), brought together many researchers interested in algebraic specifications and related topics. It provided an opportunity to present the latest, even unfinished, work and to discuss the future trends and research problems. The remarkable progress of the field re- ported at the workshop provoked this volume. The present collection of papers documents the recent developments and trends in data type and software specification in theory and in practice. The theoretical con- tributions pursue four objectives: the 1 iberation of the specification methods from the underlying logic (Sannella and Tarlecki; Maibaum and Sadler), the extension of the algebraic theory of data types to meet adequately the semantics of imperative programming languages and the idea of observabil ity (Wagner; Hennicker and Wirsing; Moller and Dosch; Streicher), the adaption of stepwise-refinement techniques to spec- ifications with loose semantics (Beierle and Voss) and error and exception handl ing (Gogolla; Poigne). The papers oriented more towards practice are harder to classify.

Dieser Sammelband erinnert an Prof. Dr. Reinhold Franck, der im M{rz 1990 bei einer Bergtour verungl}ckt ist. In seiner fachlichen Arbeit an der Universit{t Bremen hat er die Gebiete Rechnernetze und Softwaretechnik vertreten. Daneben hat er sich stark im Bereich der Informatik und Gesellschaft engagiert. Deshalb sind in diesem Band Arbeiten aus Gebieten versammelt, die sonst nicht oft aufeinandertreffen. Da zudem die Autorinnen und Autoren sowohl aus Hochschulen und Forschungseinrichtungen als auch aus der Industrie kommen, besteht der Reiz des Bandes in der Gegen}berstellung von Beitr{gen mit Softwaretechnik sowie Informatik und Gesellschaft als thematischen Schwerpunkt: eine Fundgrube im Spannungsfeld zwischen aktuellen softwaretechnischen Entwicklungen und ihren gesellschaftlichen Auswirkungen.