F# for several reasons 1) Tooling, I like proper thick IDE's like xamarins or VS. 2) better platform support (I'm serious, it isnt tied so much to windows as you might think but is one of few languages you can e.g make a 3-platform mobile app with today!). Running Haskell in the same IDE with the same compiler on several platforms is hard. Making android/iOS or web apps with it is also tricky. 3) I like ML more than Haskell, 4) trivial to slap a non-functional C# front end on F# business logic should that be necessary, much harder to do from Haskell or ML without having to resort to C/C++.