XInclude is a generic mechanism for merging XML documents, by writing inclusion tags in the "main" document to automatically include other documents or parts thereof.
[1] The resulting document becomes a single composite XML Information Set.
XInclude is not natively supported in Web browsers, but may be partially achieved by using some extra JavaScript code.
[2] For example, including the text file license.txt: in an XHTML document: gives:
This document is published under GNU Free Documentation License