The sample they showed did not look like any of the standard .NET languages, so I wonder if they are going with a standalone language. AFAIK most quantum programming languages are actually embedded into another language (C, Haskell, ML) so if they actually implemented a standalone language, that would be interesting. Not sure what the file extension means.
when you look at the example, there was also a teleport.g.cs file which looks like a standard #C file, but possibly auto-generated(?) What do you think?