The F# development home on GitHub is now dotnet/fsharp

One side of this was Visual F#, or “VisualFSharp”; a product within Visual Studio comprised of a compiler and tooling that you could use on Windows. This distinction was simple: if you’re using F# from Microsoft (i.e., on Windows via Visual Studio), it’s called Visual F#; otherwise, it’s called F#! NET Core, F# is now officially built and packaged by Microsoft in a way that is orthogonal to Visual Studio and Windows.

Source: devblogs.microsoft.com