React demo with PureScript <≡> Can be tested at https://try.purescript.org/?gist=2033fcde9c3085b87372181420f34771

Main.purs

module Main where

import Prelude

import Effect (Effect)
import Data.Maybe (Maybe(..))
import React (ReactElement)
import React.DOM (text)
import ReactDOM (render)
import Web.HTML (window)
import Web.HTML.Window (document)
import Web.HTML.HTMLDocument (body)
import Web.HTML.HTMLElement (toElement)

hello :: ReactElement
hello = text "React in PureScript"

main :: Effect Unit
main = do
  body <- map toElement <$> (window >>= document >>= body)
  case body of
    Nothing -> pure unit
    Just el -> render hello el *> pure unit