minit is an attempt to cross-breed DJ Bernstein's daemontools and init, while adding dependencies, and maintaining minimal code base. It is possible to start and stop services on the fly. minit does not depend on a mounted /proc file system, and it does not write to any part of the file system, not even to start and stop services. It does not use System V IPC, either.
GrubConf is a graphical GRUB configuration editor. It provides an easy to use interface allowing effortless modification of OSes and the flexibility to configure the most obscure options. It is designed to require minimal user interaction while providing tools for the most adventurous user.
Bootchart is a tool for performance analysis and visualization of the GNU/Linux boot process. Resource utilization data and process information are collected during the boot process, and can later be displayed in a PNG, SVG, or EPS encoded chart. Analyzing the chart will help in finding opportunities for optimization.
Yard is a suite of Perl scripts for creating rescue disks (also called bootdisks) for Linux. A rescue disk is a self-contained Linux kernel and filesystem on a floppy, usually used when you can't (or don't want to) boot off your hard disk. A rescue disk usually contains utilities for diagnosing and manipulating hard disks and filesystems.
mbootpack is a tool that takes a Multiboot kernel and modules (e.g. a Xen VMM or a xen-linux kernel and initrd), and packages them up as a single file that looks like a bzImage Linux kernel. The aim is to allow you to boot Multiboot kernels (specifically, Xen) using bootloaders that don't support the Multiboot standard (i.e. pretty much anything except GRUB).
Firewall is a set of scripts (firewall, fwup, and fwdown) that implement an ipchains firewall and various forms of network address and port translation. All you have to do is read the policy file and edit it to reflect your topology and filtering policy. It supports many different types of network topology (single host, traditional forwarding, masquerading, port forwarding, alias port forwarding and NAT), up to 10 untrusted interfaces each with their own policy, and over 50 network applications. It also supports centralised administration of multiple remote firewalls (meta-firewall).
The Auditor security collection is a live-system based on KNOPPIX. It provides tools for analyzing the security of a system. It features a menu structure that reflects the stages of a security check: foot-printing, analysis, scanning, wireless, brute-forcing, cracking. In addition to about 300 security tools, the collection includes background information regarding standard configuration and passwords, truly extensive word lists, and more mundane productivity tools.