Sometimes you have a Web application in several variants. A prominent example is the same application for different languages. In such a case, you will want to separate the common parts out and maintain them just once. Nevertheless, the variant parts should be able to reference the common parts as if they had not been factored out. This situation is the main use case for Mirrowing Folder. A mirrowing folder is a folder that is able to map one subfolder into each of its other subfolders. Under the assumption that all subfolders have essentially the same structure, the subfolders of the mirrowed folder are recursively mapped during traversal onto the corresponding subfolders in the folder selected by the request URL. Content there can access the mirrowed objects (almost) as if they were physically located beside them. Mirrowing Folder is similar to Transparent Folder but what becomes visible depends on the request URL. Therefore, name clashes are less of a problem. More information and download URL:http://www.dieter.handshake.de/pyprojects/zope/MFolder.html Dieter