Loading a new XML file into Xopus can be accomplished using the Editor.setURL function. ​The menu on the right uses a very simple line of code to load new XML documents into Xopus, here. top.document.getElementById('xopusFrame').contentWindow.Editor.setURL(this.href); First the frame where Xopus is running is found, to find the Editor object. Then a url is passed to it, using setURL. The urls of the links in the menu look like this: ​xopus-island.aspx?fileId=05_loading.xml As you can see, the island is reloaded with a new parameter.