DragonFly is an operating system and environment designed to be the logical continuation of the FreeBSD-4.x OS series. These operating systems belong in the same class as Linux in that they are based on UNIX ideals and APIs. DragonFly is a fork in the path, so to speak, giving the BSD base an opportunity to grow in an entirely new direction from the one taken in the FreeBSD-5 series.
The first release candidate of DragonFly BSD 1.0 is out: "Changes and features include: variant symbolic links, UDF support, lightweight kernel threads, message passing, GCC 3.4 in the tree, binutils 2.14, Kernighan's awk 2004-02-07, BIND 9.2.4 rc4, CVS 1.12.8, libpcap 0.8.3, tcpdump 3.8.3, less 381, MMX/XMM kernel optimisations are now on by default, greatly improving bcopy/bzero/copyin/copyout performance for large (>4K) buffers, new installer program, XIO, acpica5, new AC'97 codec support, network stack revamping, long standing bug fixes for wide variety of support and stability issues, and way, way, way more." Find more information at BSD News