Pocket Linux is an almost minimal, one floppy linux system designed to quickly convert PC workstation into secure linux-based workstation using ssh to connect to remote host (other networking clients are also supported). It supports bootp for determining host IP and other network parameters (there's also manual configuration possible, but bootp is recommended). In addition to workstations equipped with a network card (ethernet or arcnet), you can also use Pocket Linux on a PC equipped with a modem. Modem is automatically detected and then PPP connection is made.
QuickSwitch lets you switch network profiles on the fly (IP address, DNS, routes, NFS shares, etc.). There is a command-line configuration mode by which you can change your entire network setting in one line (including DNS and routing table). It is highly configurable, supports DHCP/BOOTP/NIS/NFS/etc., and also includes a curses-based GUI which you can use as a profile selector on startup.
ROCK Linux is a distribution build kit for creating Linux distributions. You can easily design and build your own distribution by choosing packages, compilers, and optimization options, and optionally enable the GCC Stack-Smashing Protector for enhanced security. It is also possible to choose custom configure options, cross-compile, and much more. Many specialized targets (customized distributions) have already been created, such as a Desktop, Router, or Minimal distribution. A variety of architectures are supported.
Owl (Openwall GNU/*/Linux) is a small security-enhanced Linux distribution for servers. Owl also makes a good base system for customized virtual machine images and embedded systems, and Owl live CDs with remote SSH access are good for recovering or installing systems (whether with Owl or not). A single Owl CD includes the full live system, installable packages, the installer program, as well as full source code and the build environment capable of rebuilding the entire system from source. Owl supports multiple architectures (x86, x86-64, SPARC, and Alpha) and offers some compatibility for packages developed for other Linux distributions. The primary approaches to security are proactive source code review, privilege reduction, privilege separation, careful selection of third-party software, safe defaults, and "hardening" to reduce the likelihood of successful exploitation of security flaws.
LooperNG is an intelligent event routing daemon. Primarily used for Network Management, this application can be used to accomplish a variety of tasks related to logging and alerting such as trap forwarding/exploding, event enrichment, converting event formats (syslog->SNMP, SNMP->flatfile, syslog->Netcool), etc. It uses a system of input and output modules to interface with the event sources/sinks and a "rules file" to control the flow of the events.
Arch Linux is an i686-optimized Linux distribution. It is lightweight and contains the latest stable versions of software. Packages are in .tar.gz format and are tracked by a package manager that is designed to allow easy package upgrades. Arch is quite streamlined compared to some other distributions. Things that are relatively unused are not kept (info pages, for example). A default Arch install leaves you with a solid base; from there, you can add packages to create the custom installation you're looking for. Arch has a package build system that allows you to easily create your own packages, which makes it very easy to rebuild a package with your own custom configuration. Arch also aims to use the newer features available to Linux users, such as reiserfs/ext3 and devfs.
Loonix is a custom Linux distribution meant for server applications. It comes with only the latest up-to-date programs and applications, all specially configured for optimal performance and ease of use. Programs are neatly organized in structured directories, and strict security rules are in place for sensitive configuration files and other data.