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.
Plash is a sandbox for running GNU/Linux programs with minimum privileges. It is suitable for running both command line and GUI programs. It can dynamically grant Gtk-based GUI applications access rights to individual files that you want to open or edit. This happens transparently through the Open/Save file chooser dialog box, by replacing GtkFileChooserDialog. Plash virtualizes the file namespace and provides per-process/per-sandbox namespaces. It can grant processes read-only or read-write access to specific files and directories, mapped at any point in the filesystem namespace. It does not require modifications to the Linux kernel.
LPAR2RRD makes historical, future trends and nearly "realtime" CPU utilization graphs of LPARs and shared CPU usage of IBM Power servers. It collects complete physical and logical configuration of all servers/LPARs. It is agent-less (it gets everything from the HMC/SDMC or IVM). It supports all kinds of logical partitions (AIX/AS400/Linux/VIOS).
blueflops is a two-floppy Linux distribution with a graphical Web browser (links) and an IRC client (rhapsody). The kernel has most of the Ethernet drivers compiled in as modules (including the PCMCIA ones) and PPP support (for dialup connections). The browser is linked with OpenSSL. The scripts are all accessible by a setup script and have a nice dialog frontend.