In the modern day business world, we see more and more complex collaboration scenarios in which multiple autonomous organizations work together. From a business perspective, we distinguish between horizontal and vertical relationships. We argue that the concept of business process is central in both forms of collaboration. From a technical perspective, we find that multiple technology classes must be combined. In this paper, we choose process management technology, agent technology and (web) service technology as an important example combination. We show that the choice of specific technologies and their combination into platform topologies is not trivial.