SALI (Sara Automatic Linux Installer) is a tool that allows you to install Linux on multiple machines at once. It support several protocols for downloading by way of aria2 to install a machine. For example, BitTorrent and rsync are supported. SALI originates from SystemImager and still uses the same philosophy. It is a scalable method for performing unattended installation. SALI is mostly used in cluster setups.
Urpkg is software to install programs in a safe and undoable way. It is able to see what files any given installation command creates, and list and remove them. You are able to restrict the installation command so that it only writes where you allow it to, and does not overwrite files from other packages. Urpkg is especially useful if you want to install programs from source, or create binary packages in an automated way. Under the hood, urpkg creates a user for each package it has to install, which prevents the installation command from run with root privileges. It can be seen as a "command tracer" that remembers what files a command created and prevents it from doing forbidden things. It is written in C but relies on some external commands, like GNU Find.
Augeas is a configuration API and editing tool. It parses common configuration files like /etc/hosts or /etc/grub.conf in their native formats and transforms them into a tree. Configuration changes are made by manipulating this tree and saving it back into native configuration files.
Fakeroot-ng runs a program while fooling it into thinking it is running with root privileges. When the program does something that only root can do (e.g. create a device file), fakeroot-ng emulates the appropriate system calls so that the program gets a consistent view of its actions. Unlike the original fakeroot, fakeroot-ng uses the ptrace interface, which means that it does not suffer some of the limitations that fakeroot does. In particular, fakeroot-ng supports chroot jails.
This is the "progress" utility from NetBSD, ported to Linux and Solaris. The progress utility allows the file I/O of progresses to be monitored. It includes support for gzip-compressed files, so "progress -z -f file.tar.gz tar xf -" would show the progress of extracting file.tar.gz.
EPOR is an extensible package organiser for Unix-like systems. It's written to trace filesystem changes (something being installed) and save this information in a simple text database (this, as any other provided feature, is customisable via the embedded Guile interpreter). Database entries contain information supplied by the command line (package name, version, etc.) and traced by filesystem changes (new directories, files, etc.). This is achieved using the "LD_PRELOAD method''.