I'd like to be able to handle versions for instances of several custom classes (like documents or articles), and I'm looking for existing products, how-tos or classes which may help me in that task.

Also, for your information : - I'd don't use CMF or CPS or Plone ! - versions creation is a manual operation, not linked with existing Version product or history management (which is lost after packing) - older versions don't have to be updatable - versions handling should be available for simple items as well as object managers (Folder, OrderedFolder...) or BTree managers (BTreeManager2...) - of course, access to old versions have to be easy, throught a simple URL...

Dunno about all of these, but the only thing I know existing is http://cvs.zope.org/Products/ZopeVersionControl/ http://dev.zope.org/Wikis/DevSite/Projects/ZopeVersionControl/FrontPage It should be pretty much implemented, though I've never used it naked. If it doesn't do what you want, you'll probably have to go it yourself, which may not be too hard if you have a subset of the general operations of versioning to support. --jcc