OBA Reference Application Packs (RAP)
Each RAP contains a reference solution architecture and a sample application that illustrate how to build an OBA using the Microsoft Office Platform.
Office Business Applications Services
Office system provides several key capabilities as services that are delivered on both client applications and also on the server. Each of these services has their own Web services interfaces. As a developer, you can take advantage of these services to cleanly integrate core business processes into Office clients and Office servers.