FJAX! Yes, FJAX. It's Flash, Javascript, and XML. I want to explain first about the meaning of JAX and what it does, then go into AJAX and FJAX and discuss what's going on within each one.

JAX

JAX technologies use Javascript and XML to dynamically update data on a webpage without needing to reload the whole webpage. This mixture of technology can be used for server-side verification, making your website load faster for its viewers. It can be used for dynamic data processing applications, such as a web-based word processor or spreadsheet program. I like it for both those reasons and then some. Considering what JAX can be used for, we'll talk about how it's implemented through an AJAX interface now.

AJAX

AJAX loads fresh content on your webpage thanks to an HTTP Request function in JavaScript. Implementing the different functions for HTML via JavaScript is a tedious project, but worth it if you do it right. It tends to be fast in loading remote data, and there's no 'blink' of the page change. The main issue is that each page must load several extra Kilobytes of data just to get AJAX support. The second issue is that on many versions of Internet Explorer, you get an ActiveX Control warning, which can scare and confuse some customers.

FJAX

FJAX uses a 1px by 1px hidden Flash 'movie' to parse and load the remote data. Thanks to built in Flash technology, this can be achieved in less than 20 lines of code, resulting in a very lightweight movie - especially compared to several kilobytes of JavaScript for doing the same thing in AJAX! It is just as widely supported, being as over 98 percent of web visitors have Flash installed on their computer. It also doesn't present the security issue with IE in many cases! 

Use this information to your advantage when you consider implementing a JAX technology on your website - it may make your visitors much happier!