What I REALLY want to know is... can it run "flow" (https://github.com/facebook/flow). Because it's very useful yet painful to install... And I don't even know if it works on Windows.
For some reason I remember there being a web version of flow that was being compiled through js_of_ocaml. Maybe I'm confusing this with another project, though.
I'm pretty sure the parser could be compiled with js_of_ocaml, but not sure if everything can be. Would need to look...