Debian From Scratch is really two related components in one. First, it's a live bootable CD image that is designed to provide a full-featured kernel and rescue environment. It includes filesystem tools, editors, C compilers, Python, Perl, and everything you need to manually install Debian on a new machine. On ix86 machines, Grub is used to boot directly from the CD. There is also a program that is used to create the DFS CD images. It is highly configurable and can be used to create other custom bootable CD or DVD images. You can include whatever kernel or packages you want.
Ivman is a flexible userspace volume manager for Linux. Originally an automounter, it can also be used to run arbitrary commands when certain devices are added to or removed from the system, when properties on existing devices change, or when devices emit conditions. Unlike gnome-volume-manager, it runs from a console. It uses D-BUS and HAL to listen for new devices, and uses pmount for mounting.
Zen Garden is a tool that watches over the installation and building of source archives. It is a fork of installwatch that has been heavily updated with modern features. It can prevent build tools from interfering with files outside the build directory and create a virtual chroot to perform installations in or backup the files the install overwrites.
deb-install is a command line tool that can install or show information about packages and files in several different formats. Whenever a program is installed using deb-install, it is converted into a .deb package beforehand, and thus can be removed with a simple "apt-get remove <name>". It currently supports apt-get, .deb, .rpm, .dsc, and .tar/.zip (source archives). Compression via gzip or bzip2 is handled automatically. If a needed tool is missing, deb-install asks whether it should install it.
toolwrap is a tool for managing package installation that extendes the functionality of Stow or Tinypackage. It makes it possible for different releases of a given application to coexist on a single workstation or be deployed on a file server. Policies files allow end-users to select which package is used when a tool is invoked from the command line.
UniPKG (Universal PaCkaGe manager) is a modular package manager. It supports the RPM, deb, Slackware TGZ, and ArchLinux package formats, and doesn't depend on any of the distribution tools or libraries. It is completely self-sufficient, as formats such as cpio or tar are reimplemented.