Windows Core OS

Windows Core OS (WCOS for short) is an internal Microsoft effort that aims to provide a universal, modular base for future versions of Microsoft Windows that are not required to be fully compatible with the original desktop variant. It builds on top of OneCore project, which unifies all products based on Windows into a single source code repository.

Planning for a common core for all Windows products started in 2002, although actual development didn't start until 2014.

List of products based on WCOS

 * Windows Andromeda
 * Windows Polaris
 * Windows 10X
 * FactoryOS