Foreword to the Third Edition

A decade ago, John Resig imagined a JavaScript library that would simplify the way people built web sites. Today, that library, jQuery, is used by more than 80% of all web sites that use JavaScript, according to BuiltWith.com. It would be hard to call yourself a web developer today without knowing jQuery.

On the technical side, jQuery simplifies the long-winded native method calls that browsers use and shrinks the number of lines of code that it takes to get things done. That’s why jQuery’s motto is “Write less, do more.” jQuery also paves over the differences in behavior—and even some outright bugs—that exist in browsers. That simplifies both development and testing.

From the start, jQuery was designed so that it could be extended by others. The jQuery plugin model lets anyone build specialized functionality on top of what jQuery already offers. There are thousands of jQuery plugins that do everything from lightboxes to form validation. The result is that many people with only a modest amount of programming skill are able to create beautiful and functional web sites by building on the work that others have done.

Still, code alone is not what made jQuery popular. From the beginning, a strong community of helpful developers filled online forums and mailing lists to answer questions for newcomers. The insight gained from those discussions led to better documentation, training classes, and books like this one.