F# and OCaml

F# and OCaml are both members of the ML language family — together with Standard ML, the three most prominent ML dialects today.

OCaml (mid-1990s) is a multi-paradigm language that unifies functional, imperative, and object-oriented programming under a strong ML-like type system. It features type inference, pattern matching, parametric polymorphism, first-class closures, and algebraic data types. It has seen commercial use in financial analysis, driver verification, industrial robotics, and static analysis of embedded software.

F# originated at Microsoft Research as a .NET implementation of a core of OCaml, designed by Don Syme. It is a functional-first language: functional programming is the default, but it fully supports imperative and object-oriented styles, and interoperates seamlessly with C# and the .NET ecosystem. It has been included in Visual Studio since 2010 and is developed by the F# Software Foundation, Microsoft, and open contributors.

The lineage is direct: ML → Caml → OCaml → F#. If you know one, the other feels familiar — pattern matching, pipe operators, immutable-by-default values, discriminated unions. The main difference is the runtime: OCaml compiles to native code, F# runs on .NET (and can also target JavaScript via Fable).