An internal initiative dubbed Andromeda OS seeks to transform Windows 10 into a much more modular platform, componentizing the operating system and allowing for improved adaptability across devices.
Composable shell RSS
CShell - the adaptive user interface that Microsoft is developing to run across all Windows 10 devices - includes Start screen and Action Center changes, and improvements to the Continuum experience.
The adaptive shell for Windows 10 that Microsoft is presumably working on is still very far off, but that hasn't stopped some from creating concepts of how it could work across devices.
Microsoft's new shell for Windows 10 is described as a "lightweight version of Windows designed for the modern computing world" - but the report raises more questions than it answers for now.
Microsoft currently maintains various UX shells for each type of device on which Windows 10 runs - but it's said to be developing a unified 'Composable Shell' that adapts the OS for all devices.