bucklescript compiler, ocaml standard libary by bucklescript and its required runtime support

Usage no npm install needed!

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BuckleScript: A JavaScript backend for OCaml focused on smooth integration and clean generated code.

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Please see the documentation site.




  • Thanks to the OCaml team, obviously, without such a beautiful yet practical language, this backend would not exist
  • Thanks to ninja-build, BuckleScript also comes with a blazing fast build tool on top of it, ninja is a truly well engineered scalable build tool
  • Thanks to Bloomberg! This project began at Bloomberg and was published in 2016; without the support of Bloomberg, it would not have happened. Now that the project has grown and developed its own community, it has moved to its own GitHub organization.



The ocaml directory contains the official OCaml compiler (version 4.02.3). Refer to its copyright and license notices for information about its licensing.

The ninja-build directory contains the official ninja-build (version 1.7.2). Refer to its copyright and license notices for information about its licensing.

BuckleScript builds on parts of js_of_ocaml:

BuckleScript builds on parts of OCaml:

These modules were adapted from ocaml/bytecomp/simplif.ml for JavaScript specific optimization purposes.

jscomp/core/js_main.ml is adapted from ocaml/driver/main.ml. It is not actively used but demonstrates that it is easy to assemble a whole compiler using the OCaml compiler libraries. It also shows how to add more compilation flags to a JS backend.

jscomp/stdlib is copied from ocaml/stdlib. It is compiled to JavaScript and included with BuckleScript.

jscomp/test is based on ocaml/testsuite.

BuckleScript unittest builds on parts of OUnit

  • jscomp/ounit is adapted from ounit, the unit test utilities are only used for dev purpose, they are not required for distribution