Touchless filesystem migration
Sun may be one of the masters in innovating IT, but Apple is certainly the undisputed master in making it trivial to use such innovations. One example: Apple has patented “touchless migration” of filesystems. This patent leverages the fact, that almost all filesystems do the same stuff: Storing and organizing data blocks. The simple, but really brilliant idea: Keeping the data blocks, leaving it untouched and write a new set of meta data around it. Voila, filesystem converted, without the backup-format-restore-cycle. Even without copying the data. So the migration should be really fast. An with the inclusion of ZFS into 10.5 such migrations will happen soon on millions of computers.