Hi Roy, Thanks a lot for your prompt, complete and enthusiastic answer. We have lots of requirements to balance and this information is of great help. When I was talking about implementing eBay I meant: if you had to implement something like eBay, would you use JBoss Portal? I ask that because we have many requirements similar to the features eBay is offering, and a huge number of hit per second. We are not getting any free PS2 games... I wonder if we should ask for them... :-) Back to the point, I would like to ask a couple more questions. According to our design it would be neccesary to have the notion of page state and some portlets having their state in the page request. Their cache expiration time would be 0 and they would render each time the page renders getting this state from the request. This way we would be abe to implement some web behaviour in the traditional way. In fact we would be implementing a per-page MVC. I find the portlet development model to be more close to a rich client application over http than a web site paradigm. This I am afraid, is not what is needed for the portal I am working on. Let´s show the issue with an example: Suppose I have a search page. In this search page I might have a portlet that shows a text box accepting keywords and a search button, and also a result list portlet on the same page beneath it. Now, let?s say the user inputs a keyword, presses the search button and obtains a list of results consisting of several pages. This mechanism involves IPC because the action is performed over the search portlet and the results list portlets needs to be re-rendered affected by the results found. The model behind the search portlet would contain the keywords and the model behind the results list portlet would have the keywords + the results page number. Now the user selects page 2, the result list porlets receives an action and changes its model to page=2. During render this value is used to display the second page. Now let?s suppose the user opens a new tab in Firefox, and issues a new search with different keywords. The new list of results also contains several pages. Afterwards the user switches back to the first tab and refreshes the page. My guess is that it will incorrectly show the first page of the second tab in the first tab. Thanks again, Regards, Waldemar View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3982795#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...