Ajax framework/Library comparisons and options: ECHO2, GWT, DOJO, PROTOTYPE, JQUERY

Ajax Framework/Library comparison and selection: ECHO2, GWT, DOJO, PROTOTYPE, JQUERY read a few English and Chinese AJAX Library/Framework comparison articles, for the convenience of choice, summed up as follows:
First, in two categories, one is the compiled class and the other is a compiler category.
ECHO2/GWT is the Java code compiled into JavaScript, at first glance very convenient, without mastering JS can make a dazzling interface. But this is only suitable for not or do not want to understand the situation of JS, for or want to fully control and customize the interface of the project is not appropriate.
In addition, there is a view that java->js conversion is a low-level language to the high-level language conversion, itself meaningless. A bit like to learn the assembly, and then find a tool to convert the assembly language code into C code to use. Although I am not fully convinced of this point, but I have been using C + +, these years only gradually discovered that Java is indeed an evolution. What's the right thing to say to someone?
In Echo2 and GWT, GWT mostly works on the client side, as little as possible with the server, suitable for large Web sites, ECHO2 believes in the "load only" credo, so there will be a large number of access to the server, suitable for enterprise applications. In addition, personally feel that ECHO2 is a more comprehensive one-stop frame, the interface is also very cool. But its development tools are charged.
Again, non-compiled categories, including Dojo, PROTOTYPE, and Jqeury, are described below:
First of all, prototype, it is relatively light weight, can make your code more simplified. The most classic is "Dollar function":
document.getElementById (' ElementID ') becomes $ (' ElementID ')
It strengthens the JS language can be developmental, reducing the threshold of learning JS.
The most fascinating thing about Dojo is its event system and rich customizable components. It can add events to various HTML elements in the form of the following statements:
Dojo.event.connect (Somenode, "onclick", Dostuff);
Because Dojo provides a powerful feature, it is divided into a number of packages that can be used separately.
jquery also provides the dollar function, its plug-in system also provides components like dojo, but it is not as concise as prototype, and there is no dojo so many components to use, but it also received two advantages, and small size, the document is complete, so that it is between the two mentioned.
So, if you need a very complete tool component please use Dojo, if you want to optimize your JS code, improve your writing skills please use prototype if you want both to use jquery