FSharp is OCaml to great extent. So if you don't have the need to stay away from MS/.NET, it is more 'open source' than the rest of MS products. MS did release Fsharp with an Open Source License.
But, it does still run on .NET.
At this point, isn't every major language controlled by one main corporate entity?
Except Python? But Python doesn't have algebraic types, or very complete pattern matching.
PHP is not controlled by one main corporate entity.
{Runs, ducks, hides. :-D}
I still believe that a variant of python that has algebraic types and pattern matching beats Rust for writing parsers quickly.
My effort has been in adding these features to a front end language that transpiles to an underlying FP language, including but not limited to Rust.