Echo2 is the next-generation of the Echo Web Framework, a platform for developing web-based applications that approach the capabilities of rich clients. The 2.0 version holds true to the core concepts of Echo while providing dramatic performance, capability, and user-experience enhancements made possible by its new Ajax-based rendering engine. Echo2 removes the developer from having to think in terms of “page-based” applications and enables him/her to develop applications using the conventional object-oriented and event-driven paradigm for user interface development. Knowledge of HTML, HTTP, and JavaScript is not required. Applications may be hosted using any Java servlet container. Echo2, like its predecessor, is open-source software distributed under the terms of the Mozilla Public License (or, if preferred, the GNU LGPL License).