The Dojo Toolkit

Official Website: https://www.dojotoolkit.org

License: Free - BSD

The Dojo Toolkit is an open-source JavaScript toolkit for building great web applications. It shortens the time between idea and implementation by providing a well conceived API and set of tools for assisting and fixing the issues experienced in everyday web development. It is lightning fast, extremely robust, and supplies a solid set of tools for DOM manipulation, Animations, Ajax, Event and keyboard normalization, Internationalization (i18n) and Accessibility (a11y). The Base of Dojo is a single, lightweight entity (26KB "across the wire"). Dojo is completely free, liberally licensed (AFL or BSD), and transparently developed by an active group of developers with a strong community presence.

No matter the size of your projects, Dojo is the ultimate scalable solution to your development woes. The built-in package system ends the headache of tracking dependencies, the build system combines and shrinks optimized "layers" of code for deployment, D.O.H. makes unit and regression testing a breeze, and the doh.robot provides a quick mechanism for automating UI testing.

The Add-ons
In addition to all the great tools available in the Base dojo.js, using the powerful package system you can add functionality to your application through simple dojo.require() calls. Dojo Core includes tools such as Drag and Drop, Advanced Ajax transports, String utilities, a powerful Data API, and hundreds of others for easily making exceptionally rich internet applications.

Endless Possibilities
The Dojo Toolkit also comes pre-packaged with a project called Dijit, a system for using and creating encapsulated and reusable components or widgets. The system provides accessible, extensible, theme-able components to drop into your web applications and sites.

In addition to the prefabricated widgets available, Dijit provides a framework for streamlining the development of your own widgets or customizing the behavior of existing widgets.

Dojo is designed to be extensible in every way by providing extension points within every component. Creating custom functionality has never been easier.

Cutting Edge Technology
Dojo delivers on the promise of Web 2.0 terms like Comet and Ajax by helping you create rich and interactive web apps. The internet is becoming less about static content and more about dynamic databases and instant feedback, which require elegant interfaces and reliable tools to operate. Web applications without offline technology become useless without an internet connection, but with Dojo Offline your users retain some functionality when not connected. Whether they're on an airplane, away from home, or just have their connection drop, offline functionality is key to having people think of your web app as a reliable tool.