This volume contains the papers presented at the 6th International Conference on Object Oriented Information Systems - OOIS 2000. The conference was hosted by London Guildhall University, London, UK on the 18 - 20 December 2000. The papers published in this volume highlight the contributions of leading researchers and practitioners in the field of Object Technology. The topics covered include: Databases and Programming Issues; Modelling and Design Issues; Electronic Commerce; XML and CORBA Issues; UML and Modelling Issues; Architectures; Patterns and Visualisation; and Measurements.