Abstract: A method, apparatus, system, and signal-bearing medium that, in an embodiment, in response to a read command directed to a first directory, a query associated with the first directory is performed against a second directory, and the results of the query are returned in response to the read command. In response to an open command directed to a file in the first directory, the associated query is performed against the second directory, and the file is found in the query results. A file handle associated with the file is then created. If the query has an associated API, an instance of the API is created and a pointer to the instance is stored in the file handle. In response to a file command directed to the file handle, if the file handle contains a pointer to the API instance, the file operation is passed to the API instance.