Chromium OS is the operating system that Google Chrome OS is built on, which powers Chromebook laptops and Chrome OS workstations. The OS is all about the web. All apps are web apps and the entire experience takes place within the browser, so users do not have to deal with installing, managing and updating programs. Each app is contained within a security sandbox and the OS verifies the integrity of its own code every time it is restarted, making it harder for malware and viruses to infect the computer. Most of all, Chromium OS is obsessed with speed. It takes out every unnecessary process and runs everything it possibly can in parallel, allowing users to go from turning on the computer to surfing the web in a few seconds.
Many Googlers use Chromebooks and Chrome OS workstations as part of their daily work.