crosskit is a set of scripts and packages for developers to create Linux systems. The project was inspired from concepts of both crosstool and gentoo but is clearly not as mature. It currently supports x86 and MIPS but obviously more will be added!
The KISS build is a very simple build system for a entire linux(/gnu/uclibc) system
It is something between an automated LSF and a gentoo distribution without adanced packaging features
It consists of a simple script that download and build for you