AJAX or Asynchronous JavaScript + XML is gaining popularity in the recent years following its extensive use in Gmail. AJAX is an efficient way of getting data from the web server and modifying the webpage based on the new data without having to load the whole page again. A single page can contain a few hundred kilobytes of data but an AJAX transaction can involve a few kilobytes only. This increases the web applications efficiency dramatically as the changes can now appear instantaneous to the user and only the parts that need to change in the display are changed. The rest of the page remains the same.

AJAX uses JavaScript as the programming language that brings together several technologies: XML, a markup language for the data sent and received, DOM or Document Object Model for the dynamic display of content, XHTML and CSS for formatting and display and the XMLHttpRequest object for asynchronous communication. AJAX is therefore not a technology in itself but a group of technologies.

With websites getting more interactive like that in Facebook, Gmail and Yahoo, AJAX has become an important part of modern web development. It is interesting to note that JavaScript and XML are not a requirement of AJAX because other programming languages that can work in a browser like VBScript are available. Also, JSON or JavaScript Object Notation is an alternative to XML.

IT students should learn to use AJAX because aside from being the group of technologies that will dominate web based development, it is also forces the student to understand each technology involved. AJAX can have a higher learning curve compared to JavaScript alone but the efficiency it brings to the website, as well as the ability to create highly interactive web applications, makes it a must in a web developer’s skills.