I'm pleased to announce the release of ZODB2 3.3 alpha 3. This release includes support for new-style persistent classes and multi-version concurrency control. It's an alpha release, so we could use feedback on the new features and helping testing them. The 3.3a3 release requires Python 2.3. It contains the code that is slated to be in Zope 2.8. This version of ZODB supports Zope 2 and Zope 3. You can download a source tarball or Windows installer from http://zope.org/Products/ZODB3.3 This release contains a lot of changes and improvements since the previous alpha releases. The transaction API and implementation have been overhauled and the persistence API has seen some changes to accommodate Zope 3. New features include persistent weak references, an add() method for ZODB connections, and explicit transaction manager objects. The news file lists the changes in more detail: http://zope.org/Products/ZODB3.3/NEWS.html The new features in 3.3 represent major changes to ZODB. Support for new-style classes means that ZODB programmers can use the new class features introduced in Python 2.2, like properties and descriptors. It also means that ZODB no longer uses ExtensionClass, which caused many subtle incompatibilities with other classes. The multi-version concurrency control feature represents the end of read conflicts. If a transaction encounters a conflict, it reads older revisions of the object rather than raising a ReadConflictError. This feature allows read-only transactions to see a consistent view of the database without need to handle read conflicts and restart the transaction. I'd also like to include a personal note: This is the last ZODB release that I will be actively involved in. I will be starting a new job next month at Google in New York City. I've enjoyed working with everyone in the ZODB and Zope communities; I'll be looking forward to the ZODB 3.3 final release along with you. Enjoy! -- Jeremy Hylton <http://www.python.org/~jeremy/>