GalliumOS is a Chromebook-specific Linux variant. It lets you put a real Linux distro on a Chromebook. My recent review of a new Chromebook feature — the ability to run Linux apps on some Chromebook models — sparked my interest in other technologies that run complete Linux distros on some Chromebooks without using ChromeOS. GalliumOS can be a handy workaround.

Source : Got a Screwdriver? GalliumOS Can Turn Chromebooks Into Linux Boxes