Here is some information about embedded Linux distributions, and kernel configuration and build systems:
Vendor distros
MontaVista CE Linux - see http://www.mvista.com/products/cee/
TimeSys LinuxLink - see http://www.timesys.com/products/index.htm
Lineo Solutions uLinux - see http://www.lineo.co.jp/eng/products-services/products/ulinux.html
Other distros
Snapgear Embedded Linux Distribution - http://www.snapgear.org/
Configuration and Build systems
OpenEmbedded - System for building full embedded images from scratch
QplusTargetBuilder - Target image builder from ETRI
LTIB - Linux Target Image Builder (by Stuart Hughes of FreeScale) - see http://savannah.nongnu.org/projects/ltib
Eagle Linux - http://www.safedesksolutions.com/eaglelinux/
- An embedded Linux distribution aimed at helping users learn Linux by creating bootable Linux images "virtually from scratch". Eagle Linux 2.3 is currently distributed as a concise, 26-page PDF documenting the creation of a minimalist, network-ready Linux image for bootable CDs,
floppies, or flash drives. See description at: http://ct.enews.deviceforge.com/rd/cts?d=207-106-2-28-5560-8662-0-0-0-1
- An embedded Linux distribution aimed at helping users learn Linux by creating bootable Linux images "virtually from scratch". Eagle Linux 2.3 is currently distributed as a concise, 26-page PDF documenting the creation of a minimalist, network-ready Linux image for bootable CDs,