Hi again! As discussed two days ago, I started working on integrating Five interfaces closer into Zope 2.8. I believe I understand the problem better now and like to propose a different way to resolve it: Current State ============= Five (now part of Zope 2.8) ships with one big interfaces.py file that contains z3 interfaces for Zope 2 core classes. (There are also some five specific interfaces in that file, but they are not subject of this proposal.) interfaces.zcml states that Zope 2 implements these interfaces, but there are no tests to verify that and in fact many of these interfaces are broken in Five 1.0. (Yesterday I checked in some fixes to the Five trunk.) So if they are used at all in Five products, they are only used as marker interfaces, not to verify implementations. I grepped through CMFonFive, SilvaDocBook and SilvaFlexibleXML: None of them use these interfaces. Goals ===== Step by step, Zope 2 should move to z3 interfaces. Where z2 interfaces exist, these should be improved and bridged to z3 interfaces. Missing interfaces should be added as z3 interfaces. Instead of maintaining competing interfaces, Five should support that process. Interface locations are identifiers, so first of all I want to get these locations right before Zope 2.8 is released. Z3 interfaces should be located in an 'interfaces' module of the corresponding package. In the Five package they are unmaintainable. So e.g. instead of Products.Five.interfaces.IObjectManager Products.Five.interfaces.IWriteLock we would have OFS.interfaces.IObjectManager webdav.interfaces.IWriteLock Proposed Solution ================= 1.) Adding ZCML that bridges existing z2 interfaces into the 'interfaces' module of their package. [Zope 2.8.0] 2.) Copying z3 interfaces from Five.interfaces to the 'interfaces' module of the corresponding package. Marking those in Five as Zope 2.7 backwards compatibility cruft. [Zope 2.8.0] 3.) Doing the same for Zope 2.7 with monkey patching code. [Five 1.0+] 4.) Making interfaces.zcml point to the new locations. [Five 1.0+] 5.) Adding unit tests that verify interfaces and implementations. [Zope 2.8.0] Risks ===== I can't see a way to provide backwards compatibility for Products.Five.interfaces.*, but as explained above I'm hopeful this doesn't break many Five products. Any comments? Cheers, Yuppie