If you're a web developer, you're probably using Firefox. While Internet Explorer still dominates market share, Firefox has become the browser of choice for developers. Why? Extensions.
Firefox's extension architecture allows developers to build powerful tools that integrate directly into the browser. These extensions can inspect HTML, debug JavaScript, test CSS changes live, and much more.
If you've been doing any web development lately, you've probably heard about jQuery. Released in 2006 by John Resig, jQuery has quickly become one of the most popular JavaScript libraries, and for good reason. It makes working with the DOM so much easier and handles browser inconsistencies beautifully.
The days of writing lengthy document.getElementById() calls and dealing with different browser implementations of XMLHttpRequest are over. jQuery provides a simple, consistent API that works across all browsers.