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However, Sakai project has been put in place just before what we must call the Ajax revolution and the Web 2.0
So, Sakais's frontend is based on old fashion « click and wait » web page paradigm.
This is imply to load a new web page for each action (the infamous HTTP round trip) which makes traditional web applications slow.
In a traditional 3 tiers Web application architecture, the server is playing a role for Data Access, Business logic and Presentation.
In fact, most of the work is done by the server. This is the classic design of tools in Sakai with technologies such as JSP,JSF and RSF.
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As many of us already know, the secret ingredient of Ajax is the XMLHttpRequest JavaScript Object which allows asynchronous requests for data to the server and updates the web page without doing a full page reload.
In a nutshell, JavaScript client code manipulates the Document Object Model (DOM) of the web page using XMLHttpRequest and callbacks to send and receive data asynchronously.
With Ajax you can decide to move all the presentation layer to the client side.
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