The 64 Studio Platform Development Kit (PDK) is a version control system for GNU/Linux distributions, allowing the creation and management of many different projects, based on Debian and Ubuntu sources. PDK is written in Python, and the source code is well commented and contains documented examples.
Alindis - A GNU/Linux Distribution is a comprehensive guide which leads the reader from zero to his/her own GNU/Linux distribution. In the course of the lecture, the reader will be able to reproduce the creation of the Alindis GNU/Linux distribution, the example implementation of the concepts shown there. The guide and the distribution together form the Alindis project.
The Amahi Home Server is a Linux home server based on Fedora (and later on Ubuntu). Your machine becomes a "Home Digital Assistant" (HDA) after the installation. It provides a growing set of community packaged apps like an iTunes server, UPnP server, calendar server, a wiki, shared network storage, network backups, a printer server, VPN, and a plug-in architecture built on Ruby on Rails.
Annvix is a secure Linux server distribution. The goal is to provide an easy-to-use server distribution with high security features including a Linux kernel with AppArmor support, gcc with stack protection, and secure defaults for all services. It also includes unique features such as running all services under runit, and auditing tools such as rsec (msec's baby brother), aide, snort, and rkhunter. It uses apt-get (for RPM) for package management.
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.