C-omega on MS
Source: https://research.microsoft.com/Comega/
C-omega, is “a research language intended to foster new thoughts and ideas about programming languages, Cw (pronounced C-omega) is a combination of what used to be X#/Xen and Polyphonic C#. It's an interesting combination of new ideas, and is most certainly worth a look.”
As I've said before, languages like Xen/X#, Polyphonic C#, Cw and many others are research languages and not a replacement of C#.