Business Process Execution Business Process Execution typically represents technological knowledge infrastructures that leverage available formal, contextual information of business processes (from e.g. Workflow Management Systems) to provide relevant knowledge to process agents. The paper _Process Oriented Knowledge Management: A Service Based Approach_ by Robert Woitsch and Dimitris Karagiannis introduces PROMOTE, a framework and a platform enabling and supporting the execution of knowledge intensive business processes. The authors utilize semantic technologies and vector functions in order to match knowledge management requirements and knowledge management services. An introduced concept for a service-based and process oriented architecture of an enterprise knowledge management system integrates the elements of the theoretical framework. _Reconciling Knowledge Management and Workflow Management Systems: The Activity-Based Knowledge Management Approach_ by Schahram Dustdar introduces _Caramba_, an activity based knowledge management approach. Based on a framework that classifies different knowledge management technologies, the author motivates the need for a consideration of activities as the central concept for the integration of knowledge and workflow management systems. The presented Caramba software demonstrates the viability of the introduced concepts. _Modeling and Implementing Pre-built Information Spaces. Architecture and Methods for Process Oriented Knowledge Management_ by Karsten Boehm, Wolf Engelbach, Joerg Haertwig, Martin Wilcken and Martin Delp presents _PREBIS_, an implementation of a business process oriented knowledge infrastructure that focuses on information provision for process agents based on contextual information about the user. The authors introduce the PREBIS modules, the kernel and a phase model that allow for the configuration of pre-built information spaces. An evaluation indicates the practical applicability of the PREBIS implementation. We hope that this special issue gives the reader an insightful overview of current concepts, methods and implementations in the emerging area of business process oriented knowledge infrastructures. The special track series BPOKI is continued in 2005 with new contributions introducing latest developments and research in the field. Graz, Austria March 2005 Markus Strohmaier Stefanie N. Lindstaedt Know-Center, Graz, Austria Page 428