JQuery - Cross Browser JavaScript library

jQuery is a fast and concise JavaScript Library that simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development. jQuery is designed to change the way that you write JavaScript.

jQuery is a cross-browser JavaScript library designed to simplify the client-side scripting of HTML.It was released in January 2006 at BarCamp NYC by John Resig.
jQuery is the most popular JavaScript library in use today.

jQuery is free, open source software, dual-licensed under the MIT License or the GNU General Public License, Version 2. jQuery's syntax is designed to make it easier to navigate a document, select DOM elements, create animations, handle events, and develop Ajax applications. jQuery also provides capabilities for developers to create plug-ins on top of the JavaScript library. This enables developers to create abstractions for low-level interaction and animation, advanced effects and high-level, theme-able widgets. The modular approach to the jQuery library allows the creation of powerful and dynamic web pages and web applications.

Including the library

The jQuery library is a single JavaScript file, containing all of its common DOM, event, effects, and Ajax functions. It can be included within a web page by linking to a local copy, or to one of the many copies available from public servers.

<script type="text/javascript" src="jquery.js"></script>

The most popular and basic way to introduce a jQuery function is to use the .ready() function.

$(document).ready(function() {
// jquery goes here
});

or the shortcut

$(function() {
// jquery goes here
});

You can download the JQuery library using the following link:
http://jquery.com/