Devil-Linux is a distribution which boots and runs completely from CDROM. The configuration can be saved to a floppy diskette or a USB pen drive. Devil Linux was originally intended to be a dedicated firewall/router but now Devil-Linux can also be used as a server for many applications. Attaching an optional hard drive is easy, and many network services are included in the distribution.
The system is designed to install without the use of a hard drive. It requires the use of a CDROM and a write-protected floppy. The CDROM provides the operating system, and the floppy provides the configuration information, via a tarball that is unpacked into the /etc directory. In this way, the system is fully configurable, yet the running system has no writeable device.
These details are provided for information only. No information here is legal advice and should not be used as such.