Debian's nslu2-utils package is a collection of various things that are useful for running Debian on the Linksys NSLU2 aka the "slug". The NSLU2 is a tiny computer that's sold as a NAS device, but that's capable of running a complete Debian system -- details here.
Most of nslu2-utils are collected from various sources, some parts like the initramfs-tools integration and the nslu2-flashkernel program (now moved into the flash-kernel package and generalised), I have written myself.
This work is part of a broader goal of mine to get Debian working on more extremely small, useful (and cheap) consumer hardware of this sort. Debian everywhere..