What is the most production-level Haskell to JavaScript compiler, to write code running in the browser? [closed]

Question

There is a more complete list here:

http://www.haskell.org/haskellwiki/The_JavaScript_Problem

and there is also Fay (although it is only a subset of haskell)

https://github.com/faylang/fay

You may find this List useful: https://github.com/jashkenas/coffee-script/wiki/List-of-languages-that-compile-to-JS

From the List:

* 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.
* jshaskell

I know its not Haskell but Coffee script is expression based and rather elegant IMHO.

I have stumbled upon this project called ghcjs

It seems promising!

Quote from the README:

Haskell to Javascript translator

Project aims to provide solution to

• compile modern Haskell libraries to Javascript files and use them in Ajax applications or
• develop entire Ajax application in Haskell language

Previous version of project is located at vir.mskhug.ru.

While GHCJS does not seem to be actively maintained, Emscripten seems to be quite current.

• Emscripten compiles LLVM bitcode to JavaScript.
• GHC's LLVM backend appears to be actively developed.
• Intuitively, to answer the question, the following pipeline might not be very far from "production quality": Haskell lexemes (-> GHC ->) LLVM lexemes (-> Emscripten ->) JavaScript lexemes

I'll admit that this is a speculative post.

This language, Roy, is perhaps not really Haskell (?), but it seems very similar:

http://roy.brianmckenna.org/

Roy seems to be alive; there are many forks in the GitHub repo: https://github.com/pufuwozu/roy
and it seems to be alive: https://github.com/pufuwozu/roy/graphs

If you're using Play Framework 2.0, then there's a plugin, Ray, to run Roy on Play Framework 2.0:

http://brianmckenna.org/blog/ray
https://github.com/pufuwozu/ray

The last commit was four months ago, which is rather long ago keeping in mind that Play Framework 2 was released perhaps 4 or 5 months ago.