[lpw25]

I think they mentioned something in the browser using js_of_ocaml at CUFP last year.

[jwatzman]

The js_of_ocaml bits are actually what are powering our interactive tutorial (http://hacklang.org/tutorial/) -- the tutorial is actually a full build of the typechecker running in your browser :) The source for it is mostly at https://github.com/facebook/hhvm/tree/master/hphp/hack/src/j... minus a little bit of glue.