A new Windows 10 Build, Build 14997 (14997.1001) has leaked online and ISO of the build is available to download and install. This build comes from a new Windows 10 testing branch “Onecore”, so tread with caution. It may impact your ability to update to new builds via Insider program and you may need to roll-back to a stable build.
This build brings some new features and changes. As discovered by those who have already installed it, the build brings Lower Blue Light Mode, Microsoft Edge Tabs expansion and new Personalization menu. There are more improvements in UI here and there.
— Necrosoft Core (@NecrosoftCore) December 25, 2016