Determine .NET runtime

NetFxRuntimeVersion.fsx

open System
open System.Reflection

let getMethod (bindingFlags: BindingFlags) (methodName: string) (t: Type): MethodInfo option =
    if t <> null then
        Some (t.GetMethod(methodName, bindingFlags))
    else
        None

let privateMethod (methodName: string) (t: Type) =
    t |> getMethod (BindingFlags.NonPublic) methodName

let privateStaticMethod (methodName: string) (t: Type) =
    t |> getMethod (BindingFlags.NonPublic ||| BindingFlags.Static) methodName


let clrVersion (): string = Environment.Version.ToString()

let monoVersion (runtime: Type): string =
    let methodGetDisplayName = runtime |> privateStaticMethod "GetDisplayName"
    match methodGetDisplayName with
    | Some (m) -> string (m.Invoke(null, null))
    | None -> "Unknown version"

let whatPlatform () =
    match Type.GetType("Mono.Runtime") with
    | null -> sprintf "CLR %s" (clrVersion ())
    | monoRuntime -> sprintf "Mono %s" (monoVersion monoRuntime)

whatPlatform()