My attempts on the 99 Haskell problems, done in orgmode.
view and edit in emacs. orgmode should already be installed in a recent installation of emacs.
to export the org file inside of emacs, do C-x C-e, then choose one of the backends like HTML or PDF.
to create haskell files, use $ tangle.sh
to test the haskell files, use
$ ghc -e main test.hs