5.Different technology options for Ajax

Considering that AJAX represents a Web application model that is defined by partial screen update and asynchronous communication, there are different technologies for building the AJAX client engine, of which JavaScript, Java, and Flash are the most commonly used. Likewise, these three technologies are the most widely used in building AJAX applications.

The Java approach ("Asynchronous Java + XML")

The Java approach typically uses a browser-based lightweight Java engine for client side processing, such as UI rendering, performing partial screen refresh and asynchronous server communication. In this approach, the UI can be defined using XML, whereas client-side application logic is programmed using standard Java.

Examples available over the Internet include:

  • Artstor.org (http://www.artstor.org): a digital library of hundreds of thousands of pieces of art work and related tools.
  • Map of the Market (http://www.smartmoney.com/marketmap/): an interactive map showing an aerial view of 1,000 U.S. and international stocks

The JavaScript/DHTML approach ("Asynchronous JavaScript + XML")

The JavaScript/DHTML approach typically uses a browser-based lightweight JavaScript library for client side processing, such as performing partial screen refresh and asynchronous background network communication. In this approach, the UI is typically defined by using DHTML and client-side application logic is programmed using JavaScript.

Some examples include Google Map (http://map.google.com) and Google Suggest (http://www.google.com/webhp?complete=1&hl=en).

The Flash approach ("Asynchrounous ActionScript + SWF")

The Flash approach typically uses a browser-based Flash engine with an ActionScript library for client side processing. In this approach, the UI is typically defined using SWF (a Macromedia proprietary binary format for defining Flash based movies) on the client side, and the client-side application logic is programmed using ActionScript.

Some examples include BroadMoor Hotel (http://www.broadmoor.com/), a Flash-based interactive hotel reservation system.