True. I was referring to similarities in things like higher-order functions, tail-recursion support, pattern matching, option types and so on.

I feel the intersection of FP features between F# and Scala is much greater than C#/Java.

"F# is mostly FP with some OO tackled on - mainly influenced by OCaml. Scala unifies both OO and FP"

So Scala is mostly OO with some FP tackled on?

In my understanding, it's hard to say. It appears to have a base semantics that you can think through as OO-like message passing or FP-like lambda calculus reduction. I assume it's implemented OO-style on the JVM, but it's hard to say whether the core language biases one side or the other.

I think that's interesting but also a big indicator of why you see such a big split-brain situation in Scala. FPers program FP-Scala, OOers program OO-Scala, but neither is dominating. As far as I can tell, Martin Odersky programs balanced OO-FP, but few others do.

scala is the unholy child of everything from oo and everything from fp (well, almost).

(but i found it hard enough to program in ocaml, which is similar to f#, because i was always torn between oo and fp parts, so maybe i am biased or just Too Dumb For Scala)