When building Mashups, you need to consider different techniques to solve the cross-domain issue that is caused by the browser's Same Origin Policy. This session gives you an overview of possible techniques to overcome that problem. Starting with client-side solutions including JSONP, iframes and usage of the browser window object, server-side solutions like Apache’s mod_rewrite module or IBM’s Ajax Proxy as well as proprietary solutions including browser plug-ins, applets, signed scripts and Internet Explorer 8’s XDomainRequest are explored. The session will also cover cross-document messaging that was added in HTML 5 and give an overview of other cross-domain access proposals.