This is where cross-toolchains for various architectures are built. buildcross is the script that does the work. You need to specify the variables and some other parameters in conf_vars.sh file to finally run it and get a toolchain. buildcross has been surrounded with many scripts and wrappers that enhaces toolchain builds, now, it's a complete build infrastructure where one only have to set packages to build in PKGLIST variable and ARCHLIST for arch lists. Build logs are kept under logs/ directory and there is a html file created telling about buildcross results that can be displayed in a webserver to easily see the results. buildcross is currently building Emdebian cross toolchains for mostly all Debian arches, if bugs do not stop us. Ah! buildcross does no output, so better run it on background and check logs/ or from the html file, just do # ./buildcross & Emdebian team