Jaxer is the Aptana Ajax Server, that's also built into Aptana Studio. Jaxer allows you to execute some of your Ajax code - HTML, JavaScript, XMLHttpRequests, etc. - on the server, before the page is served or during a callback. Now you can write your entire application, or your presentation layer, using a single, familiar Ajax codebase. It's standards-based and open-source. And if your page doesn't use any Jaxer features, it will be unaffected by running it through Jaxer.
Rich, "Ajax-style" web sites and applications offer tremendous advantages over both static web sites and desktop applications. But they can be difficult to develop, maintain, and expand.
Many of the difficulties on the client side are alleviated by Ajax libraries such as jQuery, ext, and Dojo, and by development environments such as the Aptana Studio development environement.
Jaxer completes the picture by offering a powerful Ajax Server. With Jaxer, you can: