F# is not recent but it is much undervalued; very powerful because of the ML heritage but more so because of the .NET ecosystem.
I’d argue it is recent as most people have never even heard of it. That and the just recently ironed kinks of running .NET on *nix systems.
Programming in F# was an enlightening experience. The biggest improvement came when I abandoned OOP altogether and gave myself over to programming in a functional style. Sadly, the job prospects are few and far between.