OxCaml is a set of extensions to the OCaml programming language that form Jane Street’s production compiler for performance-oriented programming. OxCaml’s primary design goals are to provide safe, convenient, predictable control over performance-critical aspects of program behavior while preserving ML-style programming ergonomics.

This tutorial will focus on key extensions in OxCaml, such as:

• fearless concurrency: additions to the type system to statically rule out data races.

• data layouts: providing more control over how data is laid out in memory and native access to vector instructions.

• allocation control: reducing GC pressure and improving cache efficiency and determinism.