altJS is a collection of languages and tools aimed at rebooting JavaScript and making it better. Everything you'll find on this page is designed to output code for use on the web or with JavaScript-enabled servers and devices. This site is a handy guide to what's new in the altJS universe, as well as a place to connect.

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Top-Ranking Languages on GitHub

(JavaScript #1, ActionScript #18)

CoffeeScript #10, HaXe #46, Objective-J #50

New Languages Based on JavaScript

These languages employ a combination of syntactic sugar and replacement syntax. They're new in the sense that they aren't ports, but don't necessarily reflect JavaScript's look-and-feel or default behavior. Some are backward-compatible supersets of JavaScript, others are not.

JavaScript Enhancements

Security Enforcement
Static Typing
Synchronous to Asynchronous (CPS)
Language Extensions

Next-Generation JavaScript

These are implementations intended to test next-generation proposals for the ECMAScript standard. They represent semi-official efforts to improve the JavaScript platform.

Ruby Ports

Python Ports

Java Ports

Lisp, Clojure & Scheme Ports

OCaml/ML Ports

Haskell Ports

Smalltalk Derivatives

C/C++ Ports



Tierless Languages (produce both client & server)

Other Projects

Tools for Compiler Writers

JavaScript Parser Generators
Javascript AST (Abstract Syntax Tree)

Created with the help of this page (started by @_clyfe) and the guys on #altJS, by @dxgriffiths