Reason (programming language)
| Reason | |
|---|---|
 | |
| Paradigms | Multi-paradigm: functional, imperative, modular, object-oriented |
| Family | ML: Caml: OCaml |
| Designed by | Jordan Walke |
| First appeared | May 16, 2016 |
| Stable release | 3.18.0 
/ June 23, 2026 |
| License | MIT |
| Filename extensions | .re, .rei |
| Website | reasonml |
| Influenced by | |
| OCaml, JavaScript | |
| Influenced | |
| ReScript | |
Reason, also known as ReasonML, is a programming language and toolchain that is part of the OCaml programming language ecosystem. Reason uses many syntax elements from JavaScript, compiles to native code using OCaml's compiler toolchain, and can compile to JavaScript using the Melange compiler.