ACLs can be used to implement very complex permission scenarios that meet the requirements of modern applications. The traditional permission concept and ACLs can be combined in a smart manner. The basic file commands (cp, mv, ls, etc.) support ACLs, as do Samba and Konqueror.
Unfortunately, many editors and file managers still lack ACL support. When copying files with Emacs, for instance, the ACLs of these files are lost. When modifying files with an editor, the ACLs of files are sometimes preserved and sometimes not, depending on the backup mode of the editor used. If the editor writes the changes to the original file, the access ACL is preserved. If the editor saves the updated contents to a new file that is subsequently renamed to the old filename, the ACLs may be lost, unless the editor supports ACLs. Except for the star archiver, there are currently no backup applications that preserve ACLs.