Dojo is a modular open source JavaScript toolkit (library), designed to ease the rapid development of JavaScript or AJAX-based applications and web sites.
Traditional Asynchronous communications (most notably via AJAX) are performed with the JavaScript command XMLHttpRequest. Dojo provides an abstracted wrapper (dojo.io.bind) around XMLHttpRequest, and uses other transports (such as hidden iFrames) and a variety of data formats as well.
When implementing Dojo, it is easy to have a user's form-entered data submitted to the server 'behind the scenes'. At that point, the server can reply with some JavaScript code that updates the presentation of the page, giving a dynamic feel to the page for the user. [more]
