OCaml

OCaml v5 brings Multicore support to the language, removing the Global Interpreter Lock (GIL). It combines functional safety with imperative speed.

When to Use

• Compilers: Rust, Haxe, and Flow are written in OCaml.
• Financial Trading: Jane Street uses OCaml for everything.
• Formal Verification: Coq proof assistant is OCaml.

Core Concepts

Strong Static Types

Inference is so good you rarely write types.

Modules (Functors)

Parametrized modules (functions that return modules).