The home-baked distribution used by Google engineers is like a light skin on top of Ubuntu Linux LTS releases. The company has been a customer of Canonical as part of the Ubuntu Advantage Program, so it shouldn’t come as a surprise.
Last year, at Debconf17, Google announced that they would be switching to a new rolling release distribution called gLinux, which is based on Debian Testing. See video here (Time: 12:00).
The news didn’t land on the ears of many until now. According to a report from MuyLinux, the new Linux distribution is developed from the source of the Debian testing packages and Google would sprinkle some garnishing of its own. For an uninterrupted migration, Google has developed an internal tool which has worked fine during the trial runs.
While the exact reason why Google is ditching Ubuntu for Debian is unclear, the switch would allow Google to have timely testing of packages and fix broken things.
Google move to gLinux is also a good news for the Debian Project as the Mountain View-based company would contribute the changes to Debian Upstream. Sadly, for Canonical, the Ubuntu-maker is about to lose a customer paying fat checks.