http://www.chromium.org/chromium-os/chromiumos-design-docs/software-architecture http://www.chromium.org/chromium-os/chromiumos-design-docs/s... According to t

http://www.chromium.org/chromium-os/chromiumos-design-docs/software-architecture http://www.chromium.org/chromium-os/chromiumos-design-docs/s... According to that it looks like they are definitely using X. They seem to have made a lot of tweaks to low level firmware too.