sentence: the native file systems of unix-like systems also support arbitrary directory hierarchies , as do , for example , apple 's hierarchical file system , and its successor hfs+ in classic mac os ( hfs + is still used in mac os x ) , the fat file system in ms-dos 2.0 and later and microsoft windows , the ntfs file system in the windows nt family of operating systems , and the ods-2 ( on-disk structure-2 ) and higher levels of the files-11 file system in openvms .