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 is not a perfect solution. It requires making a physical adjustment inside the hardware and flashing new firmware before the GalliumOS installation ISO will boot. However, it can be a handy workaround if your Chromebook does not support Linux apps and/or Android apps.
If you follow directions explicitly and can wield a screwdriver to remove the bottom panel, GalliumOS is an ingenious Linux distro that can give you the best of two computing worlds.
Read more at LinuxInsider