DragonFly BSD is a free and open-source Unix-like operating system that was forked from FreeBSD 4.8. It was created by Matthew Dillon, a former Amiga and FreeBSD developer. DragonFly BSD is known for its unique design concepts, many of which were influenced by AmigaOS. It has implemented lightweight kernel threads (LWKT), an in-kernel message passing system, and the HAMMER file system. One of its key features is the HAMMER2, a modern high-performance filesystem with instant snapshots, compression, and de-duplication. DragonFly BSD also includes virtual kernels, which provide the ability to run a full-blown kernel as a user process for managing resources or for accelerated kernel development and debugging. It has been designed with extreme SMP performance as a goal, resulting in an extremely stable, high-performance kernel that is capable of efficiently using all CPU, memory, and I/O resources.