Haskell Official Home Download
https://www.haskell.org/downloads
OSX brew
$ brew install haskell-platform
Error: No available formula for haskell-platform
We no longer package haskell-platform. Consider installing ghc
and cabal-install instead:
brew install ghc cabal-install
A binary installer is available: https://www.haskell.org/platform/mac.html
so, let's open https://www.haskell.org/platform/mac.html