Finnix is a small, self-contained, bootable Linux CD distribution ("LiveCD") for system administrators, based on Debian testing. You can use it to mount and manipulate hard drives and partitions, monitor networks, rebuild boot records, install other operating systems, and much more.
NASLite is a Network Attached Storage (NAS) server operating system designed to transform a basic computer into a dedicated file server. Utilizing highly optimized versions of Samba, uCLibc, BusyBox, and various other Linux tools, it provides SMB/CIFS, FTP, or NFS filesystem support. It accommodates multiple client OSes: Windows, Mac OS X, and Linux. NASLite offers SMART disk monitoring and large file support, and is incredibly easy to install and administer.
Nightwing allows the creation of quickly deployed wireless networks without the need to make complicated configurations. With the implementation of a Mesh technology called B.A.T.M.A.N, Nightwing allows the extension of wireless networks with a simple way of adding devices that works with minimal human intervention. It has public and private connection interfaces, and the ability to filter content using OpenDNS. It is designed with security in mind, and has low hardware requirements.
SimMon is a cross platform monitoring tool which runs on almost any OS that supports the Java Virtual Machine 1.4+. Monitoring is done through the execution of existing monitoring scripts (Perl/VBS) or existing shell commands. Currently monitoring scripts are available for Solaris, Linux, Mac OS X, and Windows based systems. Network devices can be monitored via the integrated SNMPv1 scheduler.
Ewrt is a Linux distribution for the Linksys WRT54G that was forked from the Linksys and Sveasoft code bases. It is designed to meet the needs of open wireless network operators by providing a captive portal based on NoCatSplash and large-scale management functionality on a stable and low-cost platform.
iloog is a Gentoo-based live CD targeted mainly at students and scientists. It features UnionFS filesystem support that enables you to write everywhere on the LiveCD and install extra packages, a graphical X environment through the Fluxbox window manager, many programming editors and IDEs, and a plethora of scientific applications, including Octave, Namd, Merlin, and full (La)TeX support.