Where can I find details about the new ADMX format that Windows Vista and Longhorn Server use?

A. New XML-based ADMX files, which replace the .adm files that earlier Windows versions use, let you control policy settings in Vista and Longhorn Server. An ADMX file is defined as a set of one language neutral file (.admx) and associated ADMX language resource files (.adml). This language independence helps policies display correctly in local administrator environments and tools.

Microsoft has released the schema for the new ADMX format, and you can download it at http://go.microsoft.com/fwlink/?LinkID=71180 . ADMX files will reside in the Central Store, which is replicated as part of the SYSVOL structure. This approach avoids current problems that occur when using .adm files, which are stored as part of the Group Policy Object (GPO) in the adm subfolder of the GPO and thus cause replication effort between domain controllers (DCs). With Vista and Longhorn Server, when you edit a GPO, the associated ADMX files are read from the Central Store instead of being stored with each GPO that uses them, cutting down on replication. The Central Store is optional and isn't created by default; you must manually configure it.