Introduction

AJAX is a set of web development techniques used on the client side of web development to create asynchronous web applications—web pages that can fetch their content from different servers, once the base content has been loaded. The "X" in AJAX stands for XML, but today's AJAX applications typically use JSON to encapsulate data between the client and server.

The underpinning components of AJAX are actually quite old, dating back to an ActiveX component in Internet Explorer introduced by Microsoft back in 1998.

However, the technique really gained widespread traction by 2005, when Jesse Garrett wrote his article titled Ajax: A New Approach to Web Applications. In April of 2006, the World Wide Web Consortium released the first draft standard for the XMLHttpRequest object, which is the underlying object powering all of today's AJAX applications in modern browsers.

In this chapter, we'll build a simple AJAX application that returns the latitude and...