Managed access to file system objects enables an application to request access to a file system object via a file system transformer driver, which may extend the capabilities of a file system. The file system transformer driver may be configured to convert a data file format for the file system object to a data format requested by the application. The file system transformer driver may store the file system object in an internal data format using a file system on a storage device. The file system transformer driver may receive requests from applications via an operating system instruction.