Devil Linux - Linux for Sys Admin
Devil-Linux is a CD-based Linux distribution for firewalls and routers. The goal of Devil-Linux is to have a small, customizable and secure Linux. Its main purpose is to be used as server for many applications. It doesn't have any GUI or XServer related stuff. It is mainly targeted for Sys Admin.
It could boot from CDROM or USB flash drive. The configuration could be saved in floppy or USB pen drive as the CDROM is read only. It has IPTables / Netfilter support connection tracking for firewalls. It does have facilty to create customized version of the Linux to suit your needs. User could add packages on their own preference.
Most of the code is complied using GCC. Kernel level security like chroot restrictions is provided by GRSecurity. Since graphical support is not available, the system requirement is very less. It could run loads of server related applications.
Devil Linux suits for Proxy Server, DNS Server, FTP Server, File Server, DHCP Server, Mail Server, HTTP Server and other server related application. Source code location: http://sourceforge.net/projects/devil-linux/