The document discusses building rich internet applications (RIAs) with CodeIgniter and JavaScript. It notes that RIAs can be built in various ways, such as using browsers, browser plugins, web runtime platforms, or for desktop and mobile applications. CodeIgniter is described as a good "glue language" that can quickly get projects up and running. The author's typical approach is outlined, involving tossing out views, doing most work in models, avoiding heavy controllers, and keeping the API in a separate controller. Code examples are provided for both the client-side code in AIR and Titanium, and server-side CodeIgniter code.