The RSS Blog

IEBlog: In conjunction with A9.com, we’ve also announced OpenSearch 1.1 in order to allow users to easily populate their search engine of choice. We’re working together with A9.com to provide backward compatible extensions to OpenSearch 1.0 to allow the OpenSearch to define search engines that output HTML as well as RSS. [cut] IE 7 implements a native XMLHTTPRequest object for Javascript applications.

http://blogs.msdn.com/ie/archive/2005/09/13/465338.aspx