Build an Ajax application with the Dojo Toolkit

(..) Summary: The Dojo toolkit is a JavaScript library that makes the process of building large JavaScript-based Rich Internet Applications (RIAs) much simpler. With a wide range of features—from DOM querying and manipulation, Asynchronous JavaScript and XML (Ajax) request handling, excellent object-orientation support, and a full user interface widget library (Dijit)—Dojo is an excellent library to use to build a dynamic and interactive web application. In this tutorial, learn about many of the concepts of Dojo and the Dijit widget library through the development of a fully featured sample application, a contact manager system. This application lets a user browse, create, edit, and remove contacts (and contact groups) from a MySQL database. PHP is used on the server side to communicate with the database, with Dojo and the Dijit component library providing a rich, Ajax-powered user interface. The final result is a powerful web application that you can use as a foundation for your own RIAs. (...)

http://www.ibm.com/developerworks/web/tutorials/wa-dojotoolkit/resources.html