F# is a practical choice but the language features are quite far behind OCaml now.

{Ecosystem, Functors} - choose 1

From an outsider's perspective, it feels like Ocaml has more active development of features, between the new effects system they added in 5 and all the work Janestreet is doing to let Ocaml developers have more control over performance.

F# is not stagnant thankfully, it gets updates with each new version of dotnet (though I haven't checked what is coming with dotnet 10), but I don't recall anything on the level of the above Ocaml changes in years.

Applicative Computation Expressions are a big deal (added in F# 5). Recent changes have been smaller in scope.

Unfortunately lots of the more advanced stuff seems to be blocked on C# team making a decision. They want a smooth interop story.

But F# remains a solid choice for general purpose programming. It's fast, stable and .NET is mainstream.

Oh yeah I love f#, I need to find more excuses to use it. I just wish it felt like MS was willing to invest more into it. But at least they have not abandoned it and continue to put some resources into its ongoing growth.

What about a strict subset of C#. The use case for F# seems to be shrinking because MS is putting all its energy in language.

This isn't true, because more is not always better.

C# has lots of anti-features that F# does not have.

F# also has a real slow compiler. Last time hello world took a few secs on brand new mac.