DWR, or Direct Web Remoting, is a Java open source library which helps developers write web sites that include Ajax technology. It allows code in a web browser to use Java functions running on a web server as if those functions were within the browser. It consists of two main parts: * Code to allow JavaScript to retrieve data from a servlet-based web server using Ajax principles. * A JavaScript library that makes it easier for the web site developer to dynamically update the web page with the retrieved data. Here is a sample Callback: The DWR project was started by Joe Walker in 2004.