The document discusses how to create high scalable JavaScript applications. It presents two main options - writing everything from scratch or using existing open source solutions. It then outlines several existing JavaScript libraries and frameworks that provide tools for DOM manipulation, events, animations, AJAX requests, templates, module loading, and testing. The document also discusses how these tools can be used to create an easy-to-maintain UI architecture for Java portals, highlighting the AlloyUI library and examples of its use.