Rania Khalaf  IBM Research Division, Thomas J. Watson Research Center, 19 Skyline Drive, Hawthorne, New York 10532 (rkhalafus.ibm.com). Ms. Khalaf is a software engineer in the Component Systems group at the Watson Research Center. She received her Bachelor's and Master's degrees in computer science and electrical engineering from MIT in 2000 and 2001. Her interests include component-based software engineering, workflow, and service-oriented computing, Web Services in particular. Ms. Khalaf is a co-developer and co-architect of the IBM BPEL4WS prototype implementation (BPWS4J) and the Java Record Object Model (JROM). She has published a number of papers on service-oriented computing and has served on the program committees of conferences and workshops in the field. Ms. Khalaf is pursuing her Ph.D. studies in service aggregation and composition under Prof. Dr. Frank Leymann at the University of Stuttgart while continuing to work at IBM.

Alexander Keller  IBM Thomas J. Watson Research Center, 19 Skyline Drive, Hawthorne, NY 10532 (alexkus.ibm.com). Dr. Keller is a research staff member and manages the Service Delivery Technologies department at the Watson Research Center. He received his M.Sc. and Ph.D. degrees in computer science from Technische Universität München, Germany, in 1994 and 1998, and has published more than 40 refereed papers in the area of distributed systems management. He joined the IBM Research Division in 1999. Dr. Keller's research interests revolve around change management for applications and services, information modeling for e-business systems, and SLAs (service-level agreements). He serves on several technical program and organizing committees of related conferences and workshops and is a member of the USENIX Association, the IEEE, and the DMTF CIM Applications and Metric Extensions working groups. He was a main contributor to the IBM Web Service Level Agreement (WSLA) framework, which served as the basis for the upcoming GGF WS-Agreement standard.

Frank Leymann  University of Stuttgart, Universitätsstr.38, 70569 Stuttgart, Germany and IBM Software Group, Böblingen, Germany (Frank.Leymanninformatik.uni-stuttgart.de). Prof. Dr. Leymann is a full professor of computer science and director of the Institute of Architecture of Application Systems at the University of Stuttgart, Germany. His research interests include service-oriented computing, workflow and business process management, transaction processing, and architecture patterns. Frank worked for two decades in the IBM Software Group, building database and middleware products. He was awarded the title of IBM Distinguished Engineer in 2000 and was elected to the IBM Academy of Technology in 1994. He has worked continuously on workflow technology since the late 1980s, becoming known as the father of IBM's workflow product set. He contributed heavily to the architecture and strategy of IBM's entire middleware stack and IBM's on demand computing strategy and is co-architect of the Web Services stack. He is co-author of many Web Services specifications, including WSFL, WS-Addressing, WS-MetadataExchange, WS-Business Agreement, the WS-Resource Framework, and, of course, BPEL4WS. Dr. Leymann has published many papers in journals and proceedings, co-authored three text books, and holds a multitude of patents especially in the area of workflow management and transaction processing. He served on program and organizing committees of many international conferences, and he is editor-in-chief or associated editor of several journals.