Buildroot is a set of Makefiles and patches that makes it easy generate a cross-compilation toolchain and root filesystem for your target Linux system using the uClibc C library. Buildroot is useful mainly for people working with small or embedded systems. Embedded systems often use processors that are not the regular x86 processors everyone is used to using on their PC. It can be PowerPC processors, MIPS processors, ARM processors, etc. And to be extra safe, you do not need to be root to build or run buildroot.
SkyEye is an Open Source Software Project (GPL Licence). Origin from GDB/Armulator, The goal of SkyEye is to provide an integrated simulation environment in Linux and Windows. SkyEye environment simulates typical Embedded Computer Systems (Now it supports a series ARM architecture based microprocessors and Blackfin DSP Processor). You can run some Embedded Operation System such as ARM Linux, uClinux, uc/OS-II (ucos-ii) etc. in SkyEye, and analysis or debug them at source level.
ACCESS Linux Platform (ALP) is for mobile Linux phones and wireless devices. It combines open source Linux components with proven mobile technologies from ACCESS Company, a global provider of software technologies for mobile and beyond PC markets.
Scratchbox is a cross-compilation toolkit designed to make the development of Linux applications easier. It also provides a full set of tools to integrate and cross-compile an entire Linux distribution.
Poky Linux is a GNOME environment, for the embedded application's Linux suite, and it is based on OpenEmbedded, released a set of main goal for the Gnome development program warehouse. At present, besides Poky Linux can be used under Qemu simulator, other hardware aspect can also be operated under Sharp Zaurus, and experimental at the OpenMoko Neo1973 and Nokia's N800 operating.