Is Chrome OS a Linux Distribution?
Yes. Chrome OS, and its open source variant, Chromium OS, are distributions of the Linux kernel that come packaged with various GNU, open source, and proprietary software. The Linux Foundation lists Chrome OS as a Linux Distribution as does Wikipedia. Even Free Software Foundation founder Richard Stallman, while he does not approve of Chrome OS's restrictions, recognises it as "a variant of GNU/Linux."
Some in the Linux community have criticised Chrome OS as not being a "normal" or "traditional" Linux distribution. This is true in the sense that traditional Linux distros generally provide more customization and the ability to install a wide variety of software and desktop environments. However, Chrome OS's simplistic, restrictive nature, does not mean that it is not a Linux distro.
Others criticise Google's Chrome OS as proprietary and not developed in the open. It is true that Chrome OS contains proprietary software (Flash Player, binary drivers and some Google apps), but most Linux distros include some closed source software. Chromium OS, the base of Chome OS, is developed in the open with all the source code published online and licensed under open source licenses. You can download and compile the entire OS yourself. Watch this video to see how Google developers are working with the greater Linux community to develop Chromium OS in an open fashion.
Even though many in the traditional Linux community don't particularly like Chrome OS, it doesn't stop it from being a Linux distribution. In fact, with the recent popularity of Chromebooks, it's quite possible that it is now the most widely used version of Linux on notebook computers. Chromium OS is even being used as the basis for other distributions like the popular server distribution Core OS. Recently, Chrome OS has started to gain more acceptance from the Linux community as a "real" Linux distribution.
As Chromebooks and Chrome OS grow in popularity, we are sure to hear more from the Linux community on the subject. Perhaps Chrome OS will be embraced by the community and given credit for bringing more people to Linux. Maybe even some enthusiastic developers will use Chromium OS as a basis for a truly free version of GNU/Linux that can be installed on Chromebooks and traditional computers. Only time will tell where Chrome OS will fit in the long and varied history of GNU/Linux.