This document discusses Riena and RAP, which are frameworks for building Eclipse Rich Client Platform (RCP) applications that can run as traditional desktop applications or in a web browser. It covers key concepts of Riena like its navigation model and separation of view and controller. It also explains how to convert RCP singletons to session-scoped singletons to support the web, and how to use facades to abstract platform-specific code for RCP versus RAP. The goal is to allow developers to write code once and deploy to both desktop and web.