for Windows. In order to write to NTFS file systems on macOS versions prior to Mac OS X Snow Leopard third party software is necessary. Mac OS X 10.6 (Snow Leopard) and later allow writing to NTFS file systems, but only after a non-trivial system setting change (third party software exists that automates this). Finally, macOS supports reading and writing of the exFAT file system since Mac OS X Snow Leopard, starting from version 10.6.5. OS/2 OS/2 1.2 introduced the High Performance File System (HPFS). HPFS supports mixed case file names in different code pages, long file names (255 characters), more efficient use of disk space, an architecture that keeps related items close to each other on the disk volume, less fragmentation of data, extent-based space allocation, a B+ tree structure for directories, and the root directory located at the midpoint of the disk, for faster average access. A journaled filesystem (JFS) was shipped in 1999. PC-BSD PC-BSD is a desktop version of FreeBSD, which inherits FreeBSD's ZFS support, similarly to FreeNAS. The new graphical installer of PC-BSD can handle / (root) on ZFS and RAID-Z pool installs and disk encryption using Geli right from the start in an easy convenient (GUI) way. The current PC-BSD 9.0+ 'Isotope Edition' has ZFS filesystem version 5 and ZFS storage pool version 28. Plan 9 Plan 9 from Bell Labs treats everything as a file and accesses all objects as a file would be accessed (i.e., there is no ioctl or mmap): networking, graphics, debugging, authentication, capabilities, encryption, and other services are accessed via I/O operations on file descriptors. The 9P protocol removes the difference between local and remote files. File systems in Plan 9 are organized with the help of private, per-process namespaces, allowing each process to have a different view of the many file systems that provide resources in a distributed system. The Inferno operating system shares these concepts with Plan 9. Microsoft Windows Windows makes use of the FAT, NTFS, exFAT, Live File System and ReFS file systems (the last of these is only supported and usable in Windows Server 2012, Windows Server 2016, Windows 8, Windows 8.1, and Windows 10; Windows cannot boot from it). Windows uses a drive letter abstraction at the user level to distinguish one disk or partition from another. For example, the path represents a directory on the partition represented by the letter C. Drive