Relation between ExtJS Direct and DirectJNgine

[zachery]

Am new to ExtJS Direct and DirectJNgine. The relation between them confuses me. I cannot get the overview picture.
What I know is: ExtJS is a JavaScript framework focusing on UI design. It supplies plethora APIsfor programmers. I can call these APIs without bitter.

From the official site:

Ext Direct is a platform and language agnostic technology to remote server-side methods to the client-side. Ext Direct allows for seamless communication between the client-side of an Ext JS application and all popular server platforms.

My think is: ExtJS Direct is also a subset of the APIs supplied the ExtJS team for us to use. These APIs can facilitate our work on calling server side method. But I want to dig into a little bit.

1. Server side method can be any language method, like JAVA C++ PHP etc. Direct APIs handle all possibilities to support different server side language methods?

From the official site:

DirectJNgine (or DJN, for short), is a Java based implementation of the Ext Direct API for ExtJs. ExtJs is probably one of the most powerful and attractive UIs for web-based applications, as can be seen here, as well as in many other examples. DirectJNgine makes it much easier to use the full power of Java business classes with such a powerful front-end, making Java methods directly callable from the client.

1. Since ExtJS Direct is already implemented the APIs for seamless remote method invoking. Why DirectJNgine need to implement these ExtJS Direct APIs? What does "a java based implementation of the Ext Direct API for ExtJs" mean?
2. Could you explain the relation of ExtJS Direct API and DirectJNgine API?
3. Could you kindly help me explain the two question in my post? I am really confused by these new terms like ExtJS API, ExtJS Direct API, and DirectJNgine API. What are their purpose and how they coordinate?

[evant]

See: http://www.sencha.com/forum/showthread.php?260833