1. How to build rich Internet applications with Ext JS?

Ext JS provides numerous UI elements that are essential to developing rich Internet applications (RIAs). Ext JS includes controls such as message boxes, combo boxes, data grids, and toolbars. In addition, layout managers allow you to specify how elements are displayed on a page. Additional features are available for working with forms and windows.

The include order for the JavaScript files can change if you are using other frameworks. However, Ext JS is typically included in your Web application, assuming that you've installed Ext JS in the lib/ext directory on your Web server.

2. Explain Design patterns and Ext JS?

Developers should appreciate the well-thought-out design and implementation of Ext JS. Its object-oriented design patterns influence the relationship and interactions between objects. According to Ext JS, the design patterns used in their development were highly influenced by the book, Head First Design Patterns, by Freeman and Freeman (see Resources). Developers looking at the Ext JS source code will find creational patterns, including the singleton design pattern; structural patterns, including the flyweight design pattern; and behavioral patterns, including the observer pattern.

3. Explain Ext JS browser support?

The Ext JS framework is supported in all the major Web browsers, including:

* Windows® Internet Explorer® version 6 and later.
* Mozilla Firefox version 1.5 and later (PC and Macintosh).
* Apple Safari version 2 and later.
* Opera version 9 and later (PC and Mac).

4. Explain Benefits of ExtJS?

Given the wide range of JavaScript libraries available it was important to choose the right one. We needed to choose a library that was consistent in the way that it presents information to the user, but also consistent in the way that you code using the library.

With all Ext components extending the ‘Observable' class we had the ability to write consistent code in an event-driven manner, much like writing a desktop application, not easily achieved with other libraries. What's more is that we knew it would work cross-browser, again something not easily achieved that saves countless hours on large projects.

5. What is Ext.NET?

Ext.NET is an ASP.NET component framework integrating the Ext library, current version (as of April 2014) is 2.5 which integrates Ext JS version 4.2.1

6. Can you please explain the difference between library EXT-JS , EXT-CORE , EXT-GWT?

Originally it was just Ext JS. As part of 3.x, Ext Core was factored out of Ext JS as a standalone core library, similar to jQuery, and Ext JS bundles it by default. So if you are just using Ext JS, there is no functional difference. However, you can now use Ext Core separately from the widget framework, e.g. to do web page enhancement type stuff like jQuery, or to simply roll your own app using the base lib but without the widgets. The other big difference is that while Ext JS is dual commerical / GPL licensed, Ext Core is MIT licensed (again, to be comparable to jQuery and other core libs).

Ext GWT is sort of unrelated in that it is not directly based on the same JS code base (it is based on Google's GWT Java framework, which outputs its own JS). However, the relationship is that they both offer the same widgets with the same look and feel and functional quality. They also strive for API similarity, although by the nature of the differences in the frameworks, true API parity is not possible. Ext GWT is licensed like Ext JS, and there is no Ext Core equivalent on the GWT side, you get everything with it.

7. Explain Ext Core Browser Compatibility?

Ext Core supports all major web browsers including:

Internet Explorer 6+
FireFox 1.5+ (PC, Mac)
Safari 3+
Chrome 3+
Opera 9+ (PC, Mac)

8. Explain Ext Core Features?

Ext Core is a cross-browser JavaScript library for building dynamic web pages. The Ext Core JavaScript library provides basic cross-browser abstractions for DOM querying, element selection and more. It includes:

High performance, lightweight
Clear, maintainable code
An intuitive, easy to use API
MIT Open Source licensed

9. What is Ext Core?

Ext Core Cross-Browser JavaScript Library
Ext Core is a JavaScript Library for enhancing websites.