The document discusses using Ruby on Rails to build data intensive rich internet applications (RIAs) with little code using the Netzke framework. Netzke allows defining GUI components as Ruby classes that generate corresponding Ext JS components, providing a seamless integration of server and client functionality with a single point of configuration. Benefits highlighted include reusability, extensibility, composability, and avoiding duplicating logic on the front-end and back-end. Rails setup involves copying the Ext JS library and optional icon files.