Office Business Applications (OBAs) bridge the divide between business data in line-of-business (LOB) systems and the information worker. You can think of it as a simple model that includes three major parts: the LOB system, the customized Office client that integrates with the LOB system, and the server component (essentially SharePoint) that also integrates with the LOB system.
In the March 2008 issue of MSDN Magazine, Steve Fox helps you get you started by introducing you to a core set of seven OBA solution patterns and then applying one to the design and development of an OBA.
The goal of OBA patterns is to show how you can architect and develop an OBA, show what technologies you would use within a particular pattern, and illustrate how you might go about developing your OBA. Some of the technologies involved include OpenXML, MOSS 2007, Web services, and VSTO 3.0.