8. The computer-readable storage medium of claim 6 , wherein generating the branched fragment further comprises: identifying a document transformation applicable to the first document structure, wherein the output of the document transformation is a document composed according to the second document structure; applying the transformation to the first document fragment to generate a transformed document fragment; and generating the branched fragment from the transformed document fragment.
8. The computer-readable storage medium of claim 6 , wherein generating the branched fragment further comprises: identifying a document transformation applicable to the first document structure, wherein the output of the document transformation is a document composed according to the second document structure; applying the transformation to the first document fragment to generate a transformed document fragment; and generating the branched fragment from the transformed document fragment. 9. The computer-readable storage medium of claim 8 , wherein the document transformation comprises an XSLT transformation configured to generate an output XML document from an input XML document.