Started on a more high-level `what's new` document

doc/WHATSNEW.rst

+What's new in Zope 2.12
+=======================
+
+The article explains the new high-level features and changes found in this
+version of Zope2.
+
+You can have a look at the `detailed change log <CHANGES.rst>`_ to learn
+about all minor new features and bugs being solved in this release.
+
+
+Support for newer Python versions
+---------------------------------
+
+Zope2 has supported and required Python 2.4 since its 2.9 release in
+summer 2006. Later versions of Python have so far been incompatible with
+Zope2.
+
+This version of Zope2 adds support for both Python 2.5 and 2.6 at the same
+time. As Python 2.4 is no longer maintained itself, it is no longer officially
+supported by this Zope2 version. There is however no code in Zope2 yet which
+requires Python 2.5, so applications built on top of Zope2 should still
+continue to run with Python 2.4.
+
+Python 3 is a backwards incompatible release of Python and not supported. At
+this point there is no concrete roadmap for adoption of Python 3. It is
+expected to be a question of multiple major Zope2 releases or years, though.
+
+
+Fully eggified
+--------------
+
+Zope2 itself is now fully eggified and compatible with `setuptools
+<http://pypi.python.org/pypi/setuptools>`_. You can use popular tools like
+`easy_install <http://peak.telecommunity.com/DevCenter/EasyInstall>`_ or
+`zc.buildout <http://pypi.python.org/pypi/zc.buildout>`_ to install Zope2.
+
+Releases of Zope2 can be found at and will be installable from the Python
+package index at http://pypi.python.org/pypi/Zope2.
+
+The repackaging of Zope2 into an eggified form and accompanying changes to the
+file system layout have caused a number of changes. The environment variables
+`SOFTWARE_HOME` and `ZOPE_HOME` are no longer available nor set in the control
+scripts. If you need to access data files inside the Zope2 package, you can for
+example use `import os, OFS; os.path.dirname(OFS.__file__)` to locate the files
+inside the OFS package.
+
+In general it is discouraged to rely on the `lib/python` and `Products`
+directories to make code available to the running Zope process. While these
+mechanisms continue to work, you are encouraged to use normal distutils or
+setuptools managed packages and add these to your `sys.path` using any of the
+standard Python mechanisms. To create isolated Python environments both
+`zc.buildout <http://pypi.python.org/pypi/zc.buildout>`_ and `virtualenv
+<http://pypi.python.org/pypi/virtualenv>`_ are in wide-spread use.
+
+
+Latest version of Zope Components
+---------------------------------
+
+This version of Zope2 is compatible with and is based on Zope 3.5.
+
+A major focus of the new version of the Zope component libraries was to
+refactor package dependencies to generate more maintainable and better
+structured code. Based on this effort the number of packages included by
+Zope2 could be dramatically reduced from about 120 additional packages to
+just over 60. The total code size of Zope2 and its dependencies has decreased
+by over 200,000 lines of code as a result.
+
+You can find more information about the changes in Zope 3.5 at
+http://download.zope.org/zope3.5/. Upgrade information from Zope 3.4 to 3.5
+can be found at http://docs.zope.org/zope3docs/migration/34to35.html.
+
+
+ZODB 3.9
+--------
+
+This version of Zope2 includes the latest version of the `ZODB (3.9)
+<http://pypi.python.org/pypi/ZODB3>`_. It has a multitude of new configuration
+options and bug fixes. File storages have gotten native support for blob
+storages and demo storages have been expanded extensively. There is a large
+number of options to tune ZEO servers and clients in large scale environments
+and control cache invalidation and packaging to a much wider degree.
+
+You can read more about the detailed changes in the `ZODB3 change log
+<http://pypi.python.org/pypi/ZODB3>`_ for version 3.9.
+
+
+Module cleanup
+--------------
+
+As with every release of Zope2 this version has removed various modules
+which have been deprecated in prior versions.
+
+Most notably ZClasses and supporting modules have been removed entirely from
+Zope2. As a result the persistent product registry has been optional, but is
+still enabled by default. If your application does not rely on the registry you
+can now disable the registry by specifying::
+
+  enable-product-installation off
+
+inside your `zope.conf` file. As a result Zope will no longer write any new
+transactions to your database during startup.
+
+With the upgrade to ZODB 3.9 database-level version support is no longer
+available. Many of the modules in Products.OFSP have been removed as a result.
+The low level API to load objects from the database has lost its version
+argument as a result of this.
+
+
+Documentation updates
+---------------------
+
+Zope2 now uses `Sphinx <http://sphinx.pocoo.org/>`_ to create pleasant HTML
+representations of its documentation. An effort is underway to update the
+publicly available documentation using Sphinx at http://docs.zope.org/.
+
+So far the Zope2 Book, the Zope Developers Guide and many smaller articles
+have been converted to reStructuredText and their content updated.
+
+

doc/index.rst

@@ -7,6 +7,7 @@ Contents:
 .. toctree::
    :maxdepth: 2
 
+   WHATSNEW.rst
    CHANGES.rst
    INSTALL.rst
    SECURITY.rst