JavaScript Libraries and Frameworks

In programming terms, a library is a grouping of code that provides common or additional functionality. Libraries consist of one or more files that expose objects and functions. Within a program, a developer includes or calls the library to use these additional objects and functions.

JavaScript libraries and frameworks are useful because they offload the maintenance and development of additional and enhanced functions. They help make common programming tasks easier and can also aid in smoothing out the differences and nuances in cross-browser development.

There are numerous publicly available libraries and frameworks for JavaScript. Their goal is to take difficult tasks and make them easier for programmers developing JavaScript-centric web applications. A significant advantage to using many JavaScript libraries or frameworks is that they remove the cross-browser compatibility headaches.


jQuery provides a rich feature set, powerful options, extensibility, and excellent community support. Using jQuery, which is contained in a single JavaScript file, you can add effects to your web pages, enhance usability, and make processing of data with Asynchronous JavaScript and XML (AJAX) easier.


Modernizr enables developers to use some of the more advanced features of HTML5 and CSS3 in older browsers. It uses feature detection to determine whether a given browser supports a certain widget or effect and provides an alternative means of accomplishing the task at hand.


MooTools is a very small, highly optimized library for JavaScript. MooTools differs from jQuery because it is an object-oriented framework that concentrates on providing greater modularity and code reuse, whereas jQuery focus on effects, CSS, and direct user-experience interactions. MooTools also offers many of the same effects (such as an accordion and a slider) that you find in jQuery.