AJAX, IE8 & XMLHttp Requests

Cross Origin Resource Support or CORS for short, or HTTP Access Control, available in recent browsers, allows you to make cross-domain HTTP requests; the only requirement being that you must…

Cross Origin Resource Support or CORS for short, or HTTP Access Control, available in recent browsers, allows you to make cross-domain HTTP requests; the only requirement being that you must have control over the server-side implementation of the domain targeted in your XMLHttpRequest calls.

Source: http://www.kendoui.com/blogs/teamblog/posts/11-10-03/using_cors_with_all_modern_browsers.aspx