Opa Application Framework for JavaScript
Pull request Compare This branch is 226 commits behind MLstate:master.
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.




Opa is an advanced framework for JavaScript, made of two parts:

  • A compiler from the Opa language, which features JavaScript-like syntax but introduces many enhancements;
  • A JavaScript library, which is used at runtime.

This repository contains all the sources of both the Opa compiler and the Opa library.

Getting Started

Check out the dedicated guide.

Quick build instructions

$ ./configure
$ make
$ sudo make install

should get you there. ./configure should report any missing dependencies and point you to the packages you may install to fix them (although those may depend on your distribution). make needs to be GNU make.

The main dependencies of Opa is OCaml 4.00 and Node.js >= 0.6. In case your distribution doesn't provide a recent enough version, or if you miss some other dependencies, you can use the installation_helper.sh script, which automates the download and installation of our dependencies. Try

$ tools/dependencies/installation_helper.sh --help

Amazon Image

We provide a ready to use Amazon Image for Opa.

Directory layout

  • _build: compilation target directory
  • compiler: compiler source files
  • doc: documentation source files, guidelines, and miscellaneous copyright information
  • lib: Opa standard library, plugins and binding system library source files
  • ocamllib: OCaml libraries and runtime source files
  • tools: various tools

Details of the lib directory:

  • stdlib: the Opa standard library
  • plugins: additional Opa library modules
  • opabsl: the Opa binding system library, for binding various backends (currently node and OCaml)
  • experimental: some experimental Opa libraries

Details of the doc directory:

  • copyright: some copyright information used in our binary package, which includes external software (as obtained from the dependency installation helper)
  • *-LICENSE: licenses used by the Opa project

Details of the tools directory:

  • build: build scripts and auxiliary Makefiles
  • dependencies: contains the dependency installation helper and various patches
  • dissemination: contains helper programs to run on the cloud (transitional)
  • installer: auxiliary files used to build binary packages
  • tools: contains external checking tools
  • bash: bash completion scripts
  • editors: various helper tools for popular editors
  • utils: packaging scripts, and various auxiliary tools

Other files usage:

  • *.mllib: ocamlbuild target declaration for building an ocaml lib
  • *.itarget: ocamlbuild target declaration for building a set of targets
  • tools/platform_helper.sh: some helpers to guarantee script compatibility, mostly between Linux and MacOS
  • tools/utils/install_release.sh: builds a full Opa runtime in order to make a binary package
  • tools/utils/make_package.sh: builds various kinds of binary packages from the file hierarchy created by tools/utils/install_release.sh

The build system

The build system is based on OCamlbuild; the included tools/build/Makefile.bld dynamically builds an ocamlbuild plugin and generates targets based on files tools/build/build_libs, tools/build/build_tools and tools/build/build_rules.ml.

See tools/build/Makefile.bld and tools/build/build_rules.ml for more information. All generated files are put in _build, following the same hierarchy as the source directory.

You can find more information about the build system in tools/build/README.


All bug reports, feedback, comments, contributions or remarks are welcome: http://opalang.org.

In particular, users are welcome to:

  • subscribe on the mailing list at OWASP;
  • participate in the forum at opalang.