Over the past decade, there has been a lot of work in developing middleware for integrating and automating enterprise business processes. Today, with the growth in e-commerce and the blurring of enterprise boundaries, there is renewed interest in business process coordination, especially for inter-organizational processes. This paper provides a historical perspective on technologies for intra- and interenterprise business processes, reviews the state of the art, and exposes some open research issues. We include a discussion of process-based coordination and event/rule-based coordination, and corresponding products and standards activities. We provide an overview of the rather extensive work that has been done on advanced transaction models for business processes, and of the fledgling area of business process intelligence.