Cros is a free operating system based on openSUSE. It uses the Cinnamon desktop as it's graphic user interface, and has a custom version of the Chromium web browser.
Cr OS can be distinguished from Chrome OS in the following ways.
Cr OS - An operating system based upon openSUSE, not affiliated with Google
Chrome OS - A proprietary operating system designed by Google, and designed to be installed on commercial Chrome Books.
Cr OS, pronounced (/ˌkrɒsˈlɪnəks/), was initially released in 2009. It is based upon openSUSE and has used several desktops including Gnome, and Cinnamon. It employs Zypper as it's package manager, and the latest versions of the Chromium web browser.