ZODB4 is being developed as part of the Zope3 project. There is more developer info in the Zope3 Wiki: http://dev.zope.org/Wikis/DevSite/Projects/ComponentArchitecture/ Zope3DeveloperInfo
That's one URL split over two lines.
The ZODB Wiki has more information about the development plans for ZODB4: http://www.zope.org/Wikis/ZODB/ZODB4
This version of ZODB is not compatible with ZODB3. The APIs are different and the database formats are different. Since this is an alpha release, we expect APIs will continue to change. However, we plan to provide database migration tools for the next version of ZODB; that is, it will be possible to migrate data from a database created with ZODB 4.0a1 to 4.0a2.
ZODB4 requires Python 2.2.2 or higher. It is packaged with distutils. You can use setup.py to build and install ZODB4.
ZODB4 includes unit tests based on the Python unittest module. If you checkin changes, you should verify that all the tests succeed before you checkin.
python test.py -v
Use test.py -h for usage. The test script can run selected tests, stop after the first error, run the tests in a loop, etc.
The test suite runs 1282 tests in 250 seconds on one development machine. By default, the test suite skips many tests that cover interactions between components and that take a long time to run. Add the --all option to test.py to run all the tests.
Use the Zope3 collector at http://collector.zope.org/Zope3-dev