[jerf]

The developer posted on Reddit that this was a premature release. (Clarification: That is to say, he did something like email the link to a buddy and it unexpectedly ended up on Reddit, not that it was formally released and then regretted.)

To be honest, if you're at the point where you want that sort of thing, I'd generally suggest simply downloading ghci. ISTM that all these "try it online" things are good for are making the decision of whether you want to bother with that step. (Perhaps I'm spoiled on Linux where downloading GHC or Ruby is hardly any harder than visiting a web page anyhow.)