Whats difference between library EXT-JS , EXT-CORE , EXT-GWT

Whats difference betwe开发者_StackOverflow中文版en library EXT-JS , EXT-CORE , EXT-GWT as i have worked on ext-js so please explain me in a layman language :)

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.

@bmoeskau nice explanation.

Ext Core vs Ext JS Apples and oranges. Ext Core is more of a replacement for JQuery, for when you just need basic DOM selectors, manipulations and events, without the widgets. ExtJS uses Ext Core under the covers for the low level operations.

explanation from Tim of Sencha

Ext GWT is not a wrapper over Ext JS. Ext GWT is a Java implementation that does not use any external javascript and fully leverages the GWT API. Ext GWT does share the same look and styles as Ext JS and the API is similar in many places. In GWT-EXT, the components make calls to the underlying Ext JS code which is executing just like any other Ext JS application, where in Ext GWT, the components are written in Java. Consider events, with GWT-EXT, the events are fired and managed by the Ext javascript code, while Ext GWT uses the GWT event model. Also, consider debugging, with GWT-EXT you cannot step through all the code as it runs "under the covers" in javascript. As soon as the Java code calls javascript you lose the ability to control and trace execution. With Ext GWT, the code is in Java, so you can debug your application just like any other Java application.

There is a difference between the number of widgets int Ext GWT and GWT-EXT. This gap is decreasing as many more widgets are on the way. Also, keep in mind there are many Ext GWT features that are not in Ext JS or GWT-EXT, such as its viewer and mvc code. Ext GWT uses GWT 1.5 and takes advantage of Java 1.5 using generics, enumerations, varargs, etc.