A while ago I designed and then on and off led development of Debian's new installer. It's been quite a successful project.

I wrote a d-i retrospective on the first four years of working on debian-installer in my blog, with some cool graphs.

Its website is formally http://www.debian.org/devel/debian-installer, but http://wiki.debian.org/DebianInstaller is perhaps more interesting.

The dilab was my own rack of d-i test machines. This ran on digress, the d-i regression suite, which is the most obscure part of d-i I know of, and which I wrote.