Dojo Toolkit is an open source

Open source

The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

 modular JavaScript library

JavaScript library

A JavaScript library is a library of pre-written JavaScript which allows for easier development of JavaScript-based applications, especially for AJAX and other web-centric technologies....

 (or more specifically JavaScript

JavaScript

JavaScript is a prototype-based scripting language that is dynamic, weakly typed and has first-class functions. It is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles....

 toolkit) designed to ease the rapid development of cross-platform, JavaScript/Ajax

Ajax (programming)

Ajax is a group of interrelated web development methods used on the client-side to create asynchronous web applications...

-based applications and web sites. It was started by Alex Russell, Dylan Schiemann, David Schontzler, and others in 2004 and is dual-licensed

Dual license

Multi-licensing is the practice of distributing software under two or more different sets of terms and conditions. This may mean multiple different licenses or sets of licenses. Prefixes may be used to indicate the number of licenses used, e.g...

 under the modified BSD license

BSD licenses

BSD licenses are a family of permissive free software licenses. The original license was used for the Berkeley Software Distribution , a Unix-like operating system after which it is named....

 or the Academic Free License

Academic Free License

The Academic Free License is a permissive free software license written in 2002 by Lawrence E. Rosen, the general counsel of the Open Source Initiative ....

 (≥ 2.1). The Dojo Foundation is a non-profit organization designed to promote the adoption of the toolkit.
Dojo widgets are components — comprising JavaScript

JavaScript

JavaScript is a prototype-based scripting language that is dynamic, weakly typed and has first-class functions. It is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles....

 code, HTML

HTML

HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....

 markup, and CSS

Cascading Style Sheets

Cascading Style Sheets is a style sheet language used to describe the presentation semantics of a document written in a markup language...

 style declarations — that provide cross-browser, interactive features:

• Menu
  Menu (computing)
  In computing and telecommunications, a menu is a list of commands presented to an operator by a computer or communications system. A menu is used in contrast to a command-line interface, where instructions to the computer are given in the form of commands .Choices given from a menu may be selected...
  
  s, tab
  Tab (GUI)
  In the area of graphical user interfaces , a tabbed document interface is one that allows multiple documents to be contained within a single window, using tabs as a navigational widget for switching between sets of documents...
  
  s, and tooltip
  Tooltip
  The tooltip or infotip is a common graphical user interface element. It is used in conjunction with a cursor, usually a mouse pointer. The user hovers the cursor over an item, without clicking it, and a tooltip may appear—a small "hover box" with information about the item being hovered...
  
  s
• Sortable tables
• Dynamic charts
• 2D vector drawings
  Vector graphics
  Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...
  
  
• Animated effects—fades, wipes and slides—facilities for custom animation effects
• Tree widgets that support drag-and-drop
  Drag-and-drop
  In computer graphical user interfaces, drag-and-drop is the action of selecting a virtual object by "grabbing" it and dragging it to a different location or onto another virtual object...
  
  
• Various form
  Form (web)
  A webform on a web page allows a user to enter data that is sent to a server for processing. Webforms resemble paper or database forms because internet users fill out the forms using checkboxes, radio buttons, or text fields...
  
  s and routines for validating form input
• Calendar-based date selector, time selector, and clock
• Core widgets
• Maps (geographical openlayer-based maps & dashboard vector-based maps)
• Gauges (horizontal, vertical, circular)
• Also for 3D

One important feature of Ajax applications is asynchronous communication of the browser with the server: information is exchanged and the page's presentation is updated without a need for reloading the whole page.