It's hard to contain one's frustration in seeing Windows 10X demonstrated - it's so clearly what Windows 10 Mobile could have been, especially on dual screened devices. But no, Microsoft opted for Android for the Duo (Surface Phone), leaving Windows 10X as both 'what might have been' and also 'what's to come' in terms of dual screened tablet/hybrids. Zac Bowden shows off most of the UI in the video embedded below. It's 20 minutes, so do grab a tea or coffee, but it's well worth a watch. 

As usual, click through or maximise as needed:

The biggest takeaway is that Windows 10X is cruft-free - everything that was legacy in the UI is now gone and much has been crafted from scratch.

In the rather well done video, Zac covers:

• General UI, notifications and quick settings
• Start menu changes (including pinned web sites)
• Taskbar changes and customisation
• New sounds
• Compose mode (for when the screens are one above another, in 'laptop' mode)
• The 'wonder bar', with its various modes
• Lack of cascading windows (at present)
• Light and dark themes
• File Explorer is the Windows 10 Mobile UWP app(!)
• Running legacy Win32 applications in 'Container OS' (just the parts of Windows 10 needed to run legacy apps)

Microsoft's own launch device for Windows 10X is, of course, Surface Neo, and that'll be out later this year.

Comments? Of course, if a company brings out a 10X device with twin 7" screens (say) then maybe we're not too far off the initial vision for a Windows-running 'Surface Phone' after all?