1. A network storage system comprising: data storage that stores file data and metadata associated with the file data, the file data and metadata received from at least first and second computers each running a different operating system, with each different operating system defining a different file system, wherein each of the different file systems for the first and second computers stores file data and metadata associated with the file data in corresponding first and second different formats; one or more application program interfaces (APIs) in communication with the data storage that define operations for reading and writing the file data and metadata in the first and second different formats; and a metadata handler having a library of functions that handle at least the metadata in the first and second formats, the library of functions comprising a metadata object extraction function that accesses a metadata object having populated information corresponding to all metadata fields used by the first and second formats, the populated information being in a third format different from the first and second formats, extracts the populated information from the metadata object, and cooperates with at least one of the one or more APIs to generate at least a portion of the metadata in at least one of the first and second formats from the extracted populated information.
3. The system of claim 1 , wherein the APIs comprise file system APIs for a host file system of the data storage.