First note that SOPE OFS is different from Zope OFS. Zope OFS is basically a filesystem view on the ZODB python object database while SOPE OFS is SoObject support for filesystem based entities (so basically the reverse, Zope OFS provides a FS view on objects, SOPE OFS provides an object view on FS objects)

Note that you can use any filemanager class as a storage for SOPE objects, not only NSFileManager, eg NGImap4FileManager or NGLdapFileManager. On the other side you are not required to use OFS for storing SOPE objects.

OFS itself does no caching and conflict detection beyond the life of the context, this is the task of either an own OFS subclass or of the filemanager depending on the requirements.

Class Hierarchy:
OFSBaseObject	(keeps name, container, fm and storage path)
OFSFile	(has a BLOB and attributes)
OFSImage	(different class since different methods are bound)
OFSPropertyListObject (objects stored as a plist)
OFSWebMethod	(handles component templates inside OFS)
OFSFolder	(collections of OFSFile's and OFSFolder's)
OFSFactoryContext	(keeps instantiation state)
OFSFactoryRegistry	(select a factory object)