1.1. Overview

JavaScript has seen a large resurgence in usage over the past 8 years. Developers are looking to provide their customers with a richer user experience. With the introduction of Outlook Web Access in 2000, Google Mail in 2004, and Google Maps in 2005, web developers had great examples of building highly interactive and responsive web applications using JavaScript and Asynchronous JavaScript and XML (AJAX). Those applications sparked a renewed interest in adding greater interactivity to web sites, a practice which had died out during the browser wars of the 1990s.

Unfortunately, many developers found that building this level of interactivity took a lot of effort. JavaScript behavior was not consistent across browsers, which required a lot of hacks and extensive testing. Over the past 4 years, various JavaScript frameworks were developed that simplified development by normalizing behavior across the major browsers and by providing advanced functionality using a simplified Application Programming Interface (API).