Book excerpt: Currently, the field of information systems technology is rapidly extending into several dimensions. There is the semantic dimension (including object orientation, data deduction and extended knowledge representation schemes), there is improved systems integration, and there are new tools. All these extensions aim to provide semantically richer and better engineered information systems that allow for more adequate and complete representations and thus extend the effective use of database technology to a wider class of applications. Database researchers and developers, whether they are committed to application or to system construction, are convinced that next-generation information system technology will be heavily determined by a handful of new concepts that they have to understand and work out in detail now. This volume concentrates on the following topics: - Extended data types and data models, database programming languages; - Rule-based data deduction, expert systems, knowledge bases; - Object orientation and semantic data modelling; - DB application development, methodologies and tools; - Interface technology, parallelism, interoperability, ...; - New database applications.