Chromium

Chromium OS is the open source development version of Google Chrome OS.

Chrome OS's source code was released on November 19, 2009 under the same BSD license as Chromium OS.

User interface
Chromium OS uses the new  page found in Google Chrome to open web apps. Compared to prior builds, this replaces the applications page. Chromium OS provides a clock, battery indicator and network status indicator. The key combination toggles a keyboard overlay that shows the function of all the shortcut keys used in Chromium, including task and memory managers also found in the Chrome browser, and a command-line interface that accepts common Linux commands.

Architecture
In preliminary design documents, Google describes a three-tier architecture: firmware, web browser and window manager, and system-level software and userland services.
 * The firmware contributes to fast boot time by not probing for hardware, such as floppy disk drives, that are no longer common on computers, especially netbooks. The firmware also contributes to security by verifying each step in the boot process and incorporating system recovery.
 * System-level software includes the Linux kernel that has been patched to improve boot performance. Userland software has been trimmed to essentials, with management by Upstart, which can launch services in parallel, re-spawn crashed jobs, and defer services in the interest of faster booting.
 * The window manager handles user interaction with multiple client windows much like other X window managers.

Builds
By May 2010, compiled versions of the work-in-progress source code had been downloaded from the Internet more than a million times. The most popular version entitled "Chromium OS Flow" was created by Liam McLoughlin, a then 17-year-old college student in Manchester, England, posting under the name "Hexxeh". McLoughlin's builds boot from a USB memory stick and included features that Google engineers had not yet implemented, such as support for the Java programming language.

While Google did not expect that hobbyists would use and evaluate Chromium OS ahead of its official release, Sundar Pichai, Google vice president of product management, said that "what people like Hexxeh are doing is amazing to see." Pichai said the early releases were an unintended consequence of open source development. "If you decide to do open-source projects, you have to be open all the way."

Hexxeh's work continued into the following year. He announced "Chromium OS Lime" in December 2010, and in January 2011, released "Luigi", an application designed to "jailbreak"/"root" the Google Cr-48 "Mario" prototype hardware and install a generic BIOS. The developer made the builds available in virtual machine format on March 13, 2011, the date of his most recent blog posting. With no official build of Chromium OS forthcoming from Google, Hexxeh's "Vanilla" nightly builds of Chromium OS remain the principal resource for people wanting to try Chromium OS.

In May 2011, Dell Computer also released a new build for Dell Inspiron Mini 10v netbook, following up on an earlier build released almost 18 months earlier. The build did not support audio, but was bootable from a USB drive.

Devices
Some devices have shipped with Chromium OS preinstalled. They include the Kogan Agora Chromium Laptop by the Australian company Kogan and the  Xi3 modular computer, introduced by the company of the same name.