"DMHistorical" is a set of tools to access the historical state of a ZODB. Such tools may be helpful to analyse why unwanted or unexpected changes happened and/or to selectively go back to a previous state. This implementation resolves not only the main object but also all (direct or indirect) persistent references from this object at the given time. Zope's 'History' facility on the other hand can show the state of an object at a given time but would resolve persistent references with respect to the current time. This implementation will not work for ZODB 3.2 or earlier. It has been tested with ZODB 3.4. It may (or may not) work for ZODB 3.6 or above. Download via <http://www.dieter.handshake.de/pyprojects/zope#DMHistorical> -- Dieter