DragonFly BSD is a free and open-source Unix-like operating system forked from FreeBSD 4.8. It has diverged significantly from FreeBSD, implementing lightweight kernel threads (LWKT), an in-kernel message passing system, and the HAMMER file system. Many design concepts were influenced by AmigaOS.
DragonFly BSD images are 'live', meaning these images on whatever media will boot your system and let you log in as root (no password). You can use this feature to check for hardware compatibility and play with DragonFly a little before actually installing it on your hard drive. The CD includes an installer that can be run at the console. To activate the installer, boot and login as installer.
If you use a GUI DVD, you can login as root and start a GUI with startx. Note that there is no GUI release for the current release. You will need to install Xorg directly.