How to get F# version number?
When you start up F# Interactive window in VS, you get something like:
Microsoft (R) F# 2.0 Interactive build 2.0.5.0
Copyright (c) 2002-2010 Microsoft Corporation. All Rights Reserved.
For help type #help;;
> [Loading init.fsx]
>
which includes everything you need.
To open F# interactive window one can press : Ctrl+Alt+F.
Update (5/16/2018):
Information format seems to have changed a bit in VS 2017. Language version comes in the end :
Microsoft (R) F# Interactive version 10.1.0 for F# 4.1
Copyright (c) Microsoft Corporation. All Rights Reserved.
Whilst https://stackoverflow.com/a/10985973's solution is good, I prefer somthing I can put into a build script.
As such, I use a dummy F# project and build it using msbuild. - This will show the fsc.exe command line path.
Taking that path, I then run it without any arguments and it will show the version.
There doesn't seem to be a better way.
It's written in Windows' control panel's programs and features.