This looks very cool for an alternative shell for Windows, which is what I am seeing here but in all honesty, as soon I saw the title, it was easy to get this confused with the Cairo drawing library and associating that as a potentially new Linux "Desktop Environment" as the title outlines.
The project is technically very interesting for Windows 10 customisation, but the name is very similar with another established project in the same technical area of graphics, which may cause some confusion.
Perhaps the naming of this project was derived from Microsoft Cairo that was never released. [0]
[0] https://en.wikipedia.org/wiki/Cairo_(operating_system)