Advanced JavaScript and XML (AJAX) helps build a new breed of dynamic web applications on Web 2.0. Anyone who has used Flickr, GMail, Google Suggest, or Google Maps will realize that newer dynamic web applications are emerging. These applications look and act very similar to traditional desktop applications without relying on plug-ins or browser-specific features. Web applications have traditionally been a set of HTML pages that must be reloaded to change any portion of the content. Technologies such as JavaScript programming language and cascading style sheets (CSS) have matured to the point where they can be used effectively to create very dynamic web applications that will work on all of the major browsers.

The following technologies are typically included in AJAX:

• Cascading Style Sheets (CSS), a markup language for defining the presentation style of a page, such as fonts and colors.
• JavaScript, a scripting language. One element of JavaScript technology that is key to AJAX is XMLHttpRequest, an object that is used to exchange data between the web client and web server.
• Document Object Model (DOM), which provides a logical view of a web page as a tree structure.
• XML, the format for sending data from the web server to the client. However, you can use other formats, such as HTML, JavaScript Object Notation (JSON), or plain text.
  

Pegasus InfoCorp delivers on advanced AJAX programming solutions from our offshore software develompent center in Mumbai, India. We focus on following AJAX applications areas:

1. Real-time form data validation: Form data such as user IDs, serial numbers, postal codes, or even special coupon codes that require server-side validation can be validated in a form before the user submits a form.
2. Autocompletion: A specific portion of form data such as an email address, name, or city name may be autocompleted as the user types.
3. Load on demand: Based on a client event, an HTML page can fetch more data in the background, allowing the browser to load pages more quickly.
4. Sophisticated user interface controls and effects: Controls such as trees, menus, data tables, rich text editors, calendars, and progress bars allow for better user interaction and interaction with HTML pages, generally without requiring the user to reload the page.
5. Refreshing data and server push: HTML pages may poll data from a server for up-to-date data such as scores, stock quotes, weather, or application-specific data. A client may use AJAX techniques to get a set of current data without reloading a full page. Polling is not the most effecient means of ensuring that data on a page is the most current. Emerging techniques such as Comet are being developed to provide true server-side push over HTTP by keeping a persistent connection between the client and server.
6. Partial submit: An HTML page can submit form data as needed without requiring a full page refresh.
7. Mashups: An HTML page can obtain data using a server-side proxy or by including an external script to mix external data with your application's or your service's data. For example, you can mix content or data from a third-party application such as Google Maps with your own application.
8. Page as an application: AJAX techniques can be made to create single-page applications that look and feel much like a desktop application.