Ontology mapping is seen as a solution provider in today's landscape of ontology research. As the number of ontologies that are made publicly available and accessible on the Web increases steadily, so does the need for applications to use them. A single ontology is no longer enough to support the tasks envisaged by a distributed environment like the Semantic Web. Multiple ontologies need to be accessed from several applications. Mapping could provide a common layer from which several ontologies could be accessed and hence could exchange information in semantically sound manners. Developing such mappings has been the focus of a variety of works originating from diverse communities over a number of years. In this article we comprehensively review and present these works. We also provide insights on the pragmatics of ontology mapping and elaborate on a theoretical approach for defining ontology mapping.

This paper gives an overview of electronic marketplaces which employ agent technology or similar techniques. Special attention is given to negotiation issues. A classification scheme for competitive negotiation depending on the type of the marketplace (business-to-business, business-to-consumer and consumer-to-consumer) and on the range of players (1:1, 1:n and n:m) is introduced. Furthermore, we distinguish between one-issue and multi-issue negotiation, and we consider crisp and fuzzy constraints on either negotiating side. Several existing electronic marketplaces and prototypes of marketplaces are discussed with respect to the classification schema. Our analysis shows that agent-based e-marketplaces are a promising area of e-commerce but they are still far away from real marketplaces. In conclusion we formulate some challenges for further research in the field of multi-agent electronic marketplaces with negotiation between agents.

Knowledge-based systems have often been criticised for the limited theoretical base upon which they are constructed. This view asserts that systems are often developed in an ad hoc, individual way that leads to unmaintainable, unreliable and non-rigorous systems. The last decade, however, has seen an increased effort to produce methodologies to counter this view as well as continued research into validation and verification techniques. This paper presents a brief discussion of some of the important research in knowledge-based system life cycles and development methods. Methodologies are considered and are discussed in light of two sets of quality assurance criteria.