Cascade is a Clojure web framework that is pure Clojure, functional, share-nothing, and action-oriented like Tapestry. It uses Tapestry-style templates to define views and fragments. The document outlines features like views, fragments, expansions, and actions, and discusses what is still missing like servlet integration, document generation capabilities, and additional template features. It provides links to the Cascade code on GitHub and wiki for more information.