I&#x27;d like to see Apple adopt the HAMMER2 filesystem from DragonflyBSD. It&#x27;s a very full-featured filesystem, with snapshots, file history, and hashes for integrity checking. Snapshots could integrate with Time Machine, and file history with Apple&#x27;s file versions feature.<p>It doesn&#x27;t have as many features as ZFS or Btrfs, but it&#x27;s much better than HFS+. Plus it&#x27;s BSD-licensed and unencumbered by patents, so Apple could do whatever they want with it.