The Report Application Server (RAS) processes reports that users view with the DHTML viewer. The RAS also provides ad-hoc reporting capabilities that allow users to create and modify reports over the Web.
RAS is very similar to the Page Server: it too is primarily responsible for responding to page requests by processing reports and generating encapsulated page format (EPF) pages.
However, the RAS uses an internal caching mechanism that involves no interaction with the SAP BOBJ - Cache servers.
The RAS supports the Java viewer SDKs and includes an SDK for report creation and modification, providing you with tools to build custom report interaction interfaces.