Minimal Raspbian distribution
Packages that should be installed:
libraspberrypi-bin raspberrypi-bootloader raspi-config
List of packages to remove has been moved to a blog post: Slimming an existing Raspbian install.
Suspect packages that don't appear to be removed…
libreoffice xpdf
Building an image from scratch
Buildroot has instructions for an Raspberry Pi target.
https://github.com/debian-pi/raspbian-ua-netinst: Raspbian network installer
ansible
https://github.com/escapologyBB/ansible
https://github.com/escapologyBB/ansible-raspberry-pi
http://jpmens.net/2012/06/06/configuration-management-with-ansible/
https://github.com/geerlingguy/diet-raspbian
Etc
Instantly finding a headless Raspberry Pi
Raspberry Pi 2 and Pi 3
https://wiki.ubuntu.com/ARM/RaspberryPi
https://wiki.debian.org/RaspberryPi2
Sophisticated debootstrap script, will create an image: https://github.com/drtyhlpr/rpi2-gen-image
Enclosures and mounting
UCTRONICS 19" 3U Raspberry Pi rackmount, w/ 8 mount plates. Can support up to 12 RPi w/ additional plates.