Oh and I forgot... it for sure supports Diffing capabilities (even an import algorithm for XML-documents currently that tries to find the minimum edit operation

Oh and I forgot... it for sure supports Diffing capabilities (even an import algorithm for XML-documents currently that tries to find the minimum edit operations to transform a tree into another version of the tree). Once several revisions are stored in Sirix unique IDs are used for comparison and optionally stored hashes can be used by the diffing-algorithms to skip the traversal of subtrees (if the hash-values match). That said, for XML I'm outputting an XQuery Update Script and for JSON-data I have no serialization format as of now. So it's up for discussion basically :-)