It's being actively worked on but in a branch which is slightly stale now, there are some satellite prototype projects around it also - as .NET has had such a massive upheaval in the last year a lot of time has been spent waiting for the .NET eco system to stabilise.
Ultimately it'll be in .NET core by the end of the year, with the goal of supporting SQL Server, MongoDB and Postgres and being markdown only. The plan is to make it far more extensible for user permissions and installing plugins, and a Docker image.
The demo site will be back, once someone pays for my Azure subscription :o)