This package provides base classes for folderish Archetypes / ATContentTypes content types based on B-trees, a.k.a. "large folders" in Plone. Storing content in such folders provides significant performance benefits over regular folders.
The package only contains the integration layer for the base class provided by plone.folder, however. Please see there for more detailed information.
If you are using plone.app.folder in your product you may notice that PloneTestCase will fail to setup a Plone site for your functional tests. This can be resolved by adding this line to your functional test source:
from plone.app.folder.tests import bbb
Contributors please read the document Process for Plone core's development
Sources are at the Plone code repository hosted at Github.