PureScript comes to mind. It takes a hybrid approach to handling side effects (such as console IO, AJAX requests, random number generation, etc.). I'd recommen

PureScript comes to mind. It takes a hybrid approach to handling side effects (such as console IO, AJAX requests, random number generation, etc.). I'd recommend checking out Phil Freeman's article, which provides a nice overview along with many concrete examples [0]. Unless you've had prior exposure to Haskell, I wouldn't get too hung up on the syntax--but if you're curious, the PureScript learning resources are fantastic; I wish such resources existed when I was trying to learn Haskell! And frankly, these concepts require repeated exposure, practice, and some time to marinate in your brain before their usefulness/power become clear. [0] http://www.purescript.org/learn/eff/ http://www.purescript.org/learn/eff/ [1] http://www.purescript.org/learn/ http://www.purescript.org/learn/