Portal Server: AJAX - a new approach

Firstly, what is a portal? In English, Portal is from the Latin name "porta", which means gate. In the internet, I saw many kinds of portal. Some are just a page used for aggregation information. But according to the JSR-168, Portal is defined like a desktop, on which place some windows with a title, minimized, maximized, help, edit buttons like the real windows of the Desktop in PC.
But the big problem the portals encountered are the time when user has to wait for the page to refresh when he ( she ) clicks on the minimized, maximized, help or edit buttons of a portlet. AJAX, which stands for "Asynchronous JavaScript and XML", comes to solve this problem.

The name AJAX appeard the first time on February 18, 2005 in the article of Jesse James Garrett: http://www.adaptivepath.com/publications/essays/archives/000385.php. The main purpose of AJAX is avoid the process refreshing the page when we want some more information appeared on the page, such as in mail box, we want to remove the old mails but don't want the page to refresh because the page contains many pictures.

For more information about AJAX, I think the first place you have to look at is http://en.wikipedia.org/wiki/AJAX.

When working with Sun Portal Server, I saw that it needs to be built upon AJAX techiques. The other portal server seems moving to AJAX approach.