DragonFly BSD is a fork of FreeBSD 4.8 (June of 2003, by Matthew Dillon). It is based on the same class of operating system as BSD and Linux, but it takes a different direction from the FreeBSD, NetBSD and OpenBSD series. The DragonFly project focuses on rewriting most of the major kernel subsystems with a great deal of work in nearly every subsystem, particularly the filsystem APIs and kernel core. The DragonFly project provides native clustering support in the kernel. In 2007, a new filesystem called HAMMER was developed for DragonFly. This filesystem has been designed to solve numerous issues and to add many new capabilities to DragonFly, such as fine-grained snapshots, instant crash recovery, and near real-time mirroring. The filesystem is also intended to serve as a basis for the clustering work that makes up the second phase of the project.