List of languages that compile to JS

CoffeeScript Family (& Friends)

• CoffeeScript Unfancy JavaScript

Family (share genes with CoffeeScript)

• Coco a CoffeeScript dialect that aims to be more radical and practical, also acts as a test bed for features that get imported in CoffeeScript.
• Parsec CoffeeScript is CS based on parser combinators. The project's aim is to add static metaprogramming (i.e. macros + syntax extensibility) to Coffee Script (CS), similar to how Metalua adds such features to Lua. The resulting compiler, once merged with the official compiler, should be usable as a drop-in replacement for it.

Friends (philosophically related)

• Kaffeine Enhanced Syntax for Javascript.
• Jack Making programming playful.
• Fun A programming language for realtime webapps - compiles to client-side and server-side JS

Ruby, Python

• HotRuby runs opcode, compiled by YARV on Ruby inside a web browser or in Flash.

• rb2js converts Ruby to JavaScript.

• Red writes like Ruby and runs like JavaScript

• Pyjamas Python to JS.

• Skulpt Python. Client side.

Lisp, Scheme

• Parenscript subset of Common Lisp to JS.
• ClojureScript translates code written in a very small subset of Clojure.
• Moby Scheme a Scheme running in JS.
• Sibilant Javascript with a lisp

Haskell

• UHC (Utrecht Haskell Compiler) backend converts UHC core to JavaScript, allowing the compiling of Haskell code to JS.
• YHC (York Haskell Compiler) backend, as above but with YHC core language.

Tierless (compile to complete applications)

• GWT Java to JS.
• OPA higher-order language, compiles to native + JS + database.
• Ur in the tradition of ML and Haskell.

Multitarget

• Haxe compiles to several platforms (C++, Flash, JS, Neko, PHP).
• Clue C language compiler to different runtimes (Lua, JS, Perl 5, C, Java, CL).
• Fantom Evolutionary Object Oriented language emphasizing succinct and effective APIs (JVM, CLR, JS).

Others

• Emscripten LLVM to Javascript compiler
• Objective J shares with JavaScript the same relationship that Objective-C has with the C programming language: that of being a strict, but small, superset.
• Clamato a Smalltalk dialect that is designed to operate within the JavaScript runtime.
• mobl the new language for programming the mobile web.
• Flapjax Event-driven, reactive evaluation.

Heavyweight (static types)

• MileScript a strongly-typed language similar to C# and Java, but which compiles to JS.
• Mascara enhances JavaScript with powerful features like classes, namespaces and type-checking