Hello, after much discussion[1], Thomas Lotze and I tried to implement generic copying/stacking of component registries[2], but ultimately failed due to the same issues that Martin Aspeli had already foreseen: For the general case there are way too many edge cases, especially regarding persistent registries. So we decided to solve our most immediate needs (that are not taken care of by plone.testing's stacking solution of the global registry), namely temporarily altering utility/adapter/handler registrations. We've now released this effort as gocept.zcapatch[3], and look forward to comments and further ideas about this. I also wonder whether this might eventually get another home (plone.testing? zope.component? Or, nowadays, zope.interface?), but that's for after trying it out in the real world. Wolfgang [1] http://thread.gmane.org/gmane.comp.web.zope.devel/26469/focus=26484 [2] http://svn.zope.org/zope.component/branches/wosc-test-stacking/ http://svn.zope.org/zope.interface/branches/wosc-test-stacking/ [3] http://pypi.python.org/pypi/gocept.zcapatch -- Wolfgang Schnerring · email/jabber: ws@gocept.com · software development gocept gmbh & co. kg · forsterstraße 29 · 06112 halle (saale) · germany http://gocept.com · tel +49 345 219401 0 · fax +49 345 1229889 1 Python, Pyramid, Plone, Zope - consulting, development, hosting, operations