Gallium OS is a Linux operating system optimized for running on Chromebooks. I found it to be very responsive, visually attractive and stable. Note this excellent side-by-side comparison video between GalliumOS and ChromeOS -- on the exact same computer hardware. https://www.youtube.com/watch?v=TtJJ4r6O4co (Thanks, Adam Z Lein. https://twitter.com/adamzea https://adamlein.com/)

The transcript from the "GalliumOS First Impressions" video can be found in this Google Docs file link below. (Gracious thanks to Ben Miller, http://twitter.com/chromechronicIe)

https://docs.google.com/document/d/1rMf0-xd88rJaBNNNMxJIvmrCouHiR0izRXBFEKSvthM/edit?usp=sharing