You write some simple software to do it yourself. As explained in another thread, investigate SVG (Scalable Vector Graphics). This is a graphic file whose source is only XML. So you can write a class to pull certain links to other XML files as you say and place them into another XML (the SVG). This can then be rendered by a web browser with a SVG plugin.
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com