The XMLHTTPRequest object allows for asynchronous data retrieval from web servers.  The data format is typically XML, but it works well with any text-based data.   The XMLHTTPRequest object is also a key component of AJAX (Asynchronous JavaScript and XML) applications.  We will not get into the details of AJAX, but for a quick overview I recommend reading this article.

RSS feeds are documents that adhere to a pre-defined XML structure.  Since InfoPath is based entirely on XML technology, we can use the XMLHTTPRequest object to retrieve XML documents like RSS feeds and apply an XSL transformation to transform the XML data into a format that can be loaded and displayed in an InfoPath form.