- AJAX Extended is a JavaScript class that improves the standard XMLHttpRequest features. The most important enhancement -- it breaks the cross-domain policy rules. It is possible to get data from any source, any domain and parse it with your JS scripts. Feel excited? Just keep on reading. AJAX Extended has the same properties, methods and events as the native browser implementation. You don't have to rewrite your code -- just plug in the AJAX Extended and you're in business.