Jaxer is the world's first true Ajax server. HTML, JavaScript, and CSS are native to Jaxer, as are XMLHttpRequests, JSON, DOM scripting, etc. And as a server it offers access to databases, files, and networking, as well as logging, process management, scalability, security, integration APIs, and extensibility.

* Write your entire app or site in one consistent paradigm: Ajax.
* Or keep your server-side business logic in Java, PHP, Ruby, etc. and write your presentation layer entirely in Ajax - without exposing your back-end APIs to the web.
* Use the same code or Ajax library to prepare your page on the server and later refresh its contents on the browser.
* Use the same validation logic on the server (for security) and the browser (for interactivity) so they can never get out of sync.
* Access databases, the filesystem, and sockets and protocols (e.g. smtp and xhr) across domains.
* Call server-side JavaScript directly from the browser as if it were client-side - Jaxer makes data wrapping and remote invocation transparent.
* Compensate for limited browsers by running the page on the server and serving the static HTML.
* Overlay Jaxer on top of any other web platform: post-process existing web pages to add functionality without altering their source.

For more info, http://aptana.com/jaxer