Ajax calls are just like any other HTTP request that might be used to build a web page. However, due to their dynamic nature people often overlook the benefit of caching them.
Rule 14 of High Performance Web Sites states:
Make Ajax Cacheable
Make sure your Ajax requests follow the performance guidelines, especially having a far future [...]
We’ve added a page to our HTTP Gallery that provides an introduction to Ajax and some simple working examples. The new page is available here:
http://www.httpwatch.com/httpgallery/ajax/
BTW, you can view the AJAX requests made by this page using the free Basic Edition of HttpWatch.
Web 2.0 is a term often used to describe next generation web sites that have moved beyond the simple page request->process->response cycle and are utilizing services on the web server to return data that can be rendered without making page transitions. The result is often a more responsive user interface that closely mimics a desktop application.
The [...]